Wikispaces : chessprogramming - items matching description

Ananse

GerdIsenberg — Fri, 08 Jan 2016 15:55:58 GMT

Home * Engines * Ananse

		Ananse, a chess program by Walter Bannerman, which played various World Microcomputer Chess Championships, International Paderborn Computer Chess Championships and four consecutive Aegon Tournaments from 1993 to 1996. While Ananse did quite well against humans, in computer tournaments it often suffered from bugs, also due to premature, not well enough tested program changes between rounds, once even running Ananse under a debugger with breakpoints enabled (WMCCC 1995). Competing programmers, who seemed obligated to win with their programs, often got nervous when Ananse played a good book line and opening, for instance during the WMCCC 1996 in Jakarta, Frans Morsch in the game of Ananse versus Fritz. Ananse 5 is the current version for sale ^[1] with its own graphical user interface.
Ananse and the Tiger ^[2]

Description

given in 1997 from the ICGA site ^[3] :

200K code, 62K data. Basic alpha-beta search with several special routines providing a 'human touch'. Plays very much like a human player, even in the middle game. Search depth : 6 to 15 ply. No hash tables.

Best tournament results : 2 and a half points at Aegon 1993 and 2 points at Aegon 1994, plus several misses in Jakarta '96 (due to bugs) and a good game against Fritz 4. The current version is the best ever. Many improvements with the help of participants in Geneva the last 2 human tournaments in Geneva, where Ananse was the only participating program.

The Fritz Game

[Event "14th World Microcomputer Chess Championship"]
[Site "Jakarta, Indonesia"]
[Date "1996.10.??"]
[Round "4"]
[White "Ananse"]
[Black "Fritz"]
[Result "0-1"]
 
1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. Nf3 Nd7 7. h4 h6 8. h5 Bh7
9. Bd3 Bxd3 10. Qxd3 Qc7 11. Bd2 e6 12. O-O-O Ngf6 13. Ne4 O-O-O 14. g3 Be7 15. Nxf6 Nxf6
16. Bf4 Qa5 17. Qc4 Qd5 18. Qxd5 Nxd5 19. Bd2 Nf6 20. Be3 Ng4 21. Ne5 Nxe3 22. fxe3 Rhf8
23. Rhf1 Bf6 24. Ng4 Bg5 25. Rd3 f6 26. Rf3 f5 27. Ne5 Kc7 28. g4 fxg4 29. Rxf8 Rxf8
30. Nxg4 Rf3 31. Kd2 Rh3 32. Ne5 Rxh5 33. Nf3 Bf6 34. e4 g5 35. e5 Be7 36. c3 g4
37. c4 gxf3 38. Rxf3 c5 39. Kd3 cxd4 40. Rf7 Kd7 41. Kxd4 Rh2 42. Kc3 h5 43. Rh7 h4
44. Rh8 Re2 45. Rb8 Bd8 46. Rxb7+ Bc7 47. Kd3 h3 48. Kxe2 h2 49. Rxa7 0-1

Forum Posts

Info on Ananse by Willie Wood, CCC, November 06, 1997

External Links

References

What links here?

Page	Date Edited
4th Computer Olympiad	Jul 15, 2017
Aegon 1993	Mar 26, 2017
Aegon 1994	Mar 26, 2017
Aegon 1995	Apr 6, 2017
Aegon 1996	Jan 22, 2017
Ananse	Jan 8, 2016
Arachne	May 22, 2016
Engines	Mar 10, 2018
IPCCC 1994	Jul 31, 2013
IPCCC 1997	Aug 24, 2013
Walter Bannerman	Jan 8, 2016
WMCCC 1995	Jan 3, 2018
WMCCC 1996	Sep 15, 2016
WMCCC 1997	Apr 4, 2017

Up one level

BBchess

GerdIsenberg — Sun, 30 Oct 2011 10:26:01 GMT

Home * Engines * BBchess

BBchess,
a chess program by Bernard Brioit. The engine part is written in Pascal, its own GUI in Delphi. BBchess uses the 0x88 Board representation and performs an improved MTD(f) search on top of iterative deepening and applies Null move pruning with a depth reduction of 3. It uses two transposition tables, and supports the Thompson endgame databases with three and four pieces ^[1].

Namesake

BBChess by Borko Bošković

External Links

Gazet Jean-François from Blitzchess.fr et Mesjeuxelectroniques.fr

References

^ Interview with BBChess programmer Bernhard Brioit ... (May 31th, 2002 Deutsch, Français, English) by Frank Quisinsky from the Schachwerkstatt Archives, September 4, 2006 (dead link)

What links here?

Page	Date Edited
BB	Jan 8, 2016
BBchess	Oct 30, 2011
BBChess (SI)	Jan 12, 2015
Bernard Brioit	Jan 10, 2015
Engines	Mar 10, 2018
FCCC 1996	Jul 25, 2014
FCCC 1998	Oct 22, 2012
FCCC 1999	Jan 29, 2013
FCCC 2000	Jan 26, 2013
FCCC 2002	Aug 4, 2013
FCCC 2003	Jan 26, 2013
FCCC 2004	Jun 16, 2013
Kristy Lenix	Nov 28, 2015
Massy 2001	Jan 28, 2013
Massy 2002	Jan 2, 2018
Massy 2003	Jan 27, 2013
Massy 2004	Oct 27, 2016
Massy 2005	Jan 29, 2013
Massy 2006	Jan 29, 2013
PixChess	Oct 27, 2016

Up one Level

Bestia

GerdIsenberg — Sat, 05 Jan 2013 17:15:26 GMT

Home * Engines * Bestia

		Bestia, a Chess Engine Communication Protocol compliant chess engine written by George Lyapko in Pascal and compiled with Delphi ^[1], first released in July 2000 ^[2], with executables to run under Windows, and more recently, to x86-64 Mac OS ^[3]. Beside the transposition table, Bestia features a pawn hash table, and is able to learn from its failures ^[4] ^[5]. Bestia participated at three Hungarian Chessprogram Open, and won two times operated by Gábor Szõts, the MASPV 2001 and the MASPV 2003, both with a 100% score.
Number of the beast ^[6]

Photos & Games

MASPV 2003, round 4, Bestia - Merlin ^[7] Gábor Szõts and Balázs Jákó ^[8]

[Event "MASPV 2003"]
[Site " Sopron, Hungary"]
[Date "2003.04.19"]
[Round "4"]
[White "Bestia_094"]
[Black "Merlin"]
[Result "1-0"]
 
1.d4 d6 2.e4 g6 3.Nc3 Nf6 4.Be3 a6 5.Nf3 Bg7 6.a4 Nbd7 7.Bc4 O-O 8.e5 
dxe5 9.dxe5 Ng4 10.e6 Nde5 11.exf7+ Nxf7 12.Ng5 Qxd1+ 13.Rxd1 Ne5
14.Bd5 c6 15.Bb3 Kh8 16.O-O Nxg5 17.Bxg5 Bg4 18.f3 Bxf3 19.gxf3 Nxf3+
20.Rxf3 Rxf3 21.Bxe7 Re8 22.Rd7 Bxc3 23.bxc3 b6 24.Kg2 Rf5 25.Be6 Rf4
26.Bg5 Rff8 27.Bf7 Rxf7 28.Rxf7 Kg8 29.Rf6 Rc8 30.Be3 b5 31.a5 Kg7
32.Rd6 Kg8 33.Kf3 Rf8+ 34.Ke2 Rc8 35.Rd7 Re8 36.Ra7 Re4 37.Rxa6 Kf7
38.Rxc6 Ke8 39.Rb6 Ra4 40.Rxb5 Kd7 41.Kd3 Ra1 42.Rb7+ Kc8 43.Ra7 h5
44.a6 Kb8 45.Rb7+ Ka8 46.Rb6 Rd1+ 47.Ke2 Rd8 48.Rxg6 Rh8 49.h4 Kb8
50.a7+ Ka8 51.Bd4 Rf8 52.Rg5 Re8+ 53.Kd3 Rf8 54.c4 Rf3+ 55.Ke4 Rf8
56.Rxh5 Rc8 57.Re5 Rg8 58.h5 Rg4+ 59.Kd3 Rg3+ 60.Be3 Rg8 61.h6 Rc8
62.h7 Rh8 63.Rb5 1-0

Forum Posts

New WB engine "Bestia" available for download by George Lyapko, Winboard Forum, July 05, 2000
Surpising result from Bestia v0.2d by George Lyapko, Winboard Forum, September 06, 2000
Bestia v0.3d available by George Lyapko, Winboard Forum, September 26, 2000
Bestia lives up to its name by Dann Corbit, Winboard Forum, January 31, 2001
Bestia 0.3H verses Quark 1.15 Alpha by Dann Corbit, Winboard Forum, February 05, 2001 » Quark
Bestia 0.8 available for download by George Lyapko, Winboard Forum, July 20, 2001
Commented games Utzinger-Bestia 0.8 [40'/40] 1-0 by Kurt Utzinger, CCC, November 27, 2001
Stalemate trap(SOS-Delfi) by George Lyapko, Winboard Forum, December 18, 2001 » Stalemate, Test-Positions, SOS, Delfi
Which is the strongest Delphi chess program? by Andreas Herrmann, Winboard Forum, March 14, 2002 » Delphi
Bestia 0.90 vs Ufim 3.02 (1) 120'/40 (1/2) Commented game by Kurt Utzinger, Winboard Forum, March 04, 2003 » Ufim
Bestia 0.90 vs Ufim 3.02 (3) 120'/40 (1-0) Commented game by Kurt Utzinger, Winboard Forum, March 07, 2003
Bestia 0.90 vs Ufim 3.02 (5) 120'/40 [0-1] Commented game by Kurt Utzinger, Winboard Forum, March 08, 2003
Ufim 3.02 vs Bestia 090 (8) 120'/40 [1-0] Commented game by Kurt Utzinger, Winboard Forum, March 10, 2003
MASPV results - The champion is Bestia! by Gábor Szõts, Winboard Forum, April 22, 2003 » MASPV 2003
Olympiads 2004 : Bestia Nationality by Nicolas Normand, Winboard Forum, March 08, 2004
Re: How is learning triggered? by George Lyapko, Winboard Forum, May 25, 2006

External Links

Chess Engine

Free Winboard engine Bestia
Free Winboard engine Bestia from Wayback Machine
Bestia from WBEC Ridderkerk
Bestia 0.90 in CCRL 40/4
Bestia 0.90 in KCEC

Bestia Misc

Beast

References

^ MASPV 2001
^ New WB engine "Bestia" available for download by George Lyapko, Winboard Forum, July 05, 2000
^ Chess Engine List from Ron Murawski's Computer-Chess Wiki
^ Re: How is learning triggered? by George Lyapko, Winboard Forum, May 25, 2006
^ Bestia from WBEC Ridderkerk
^ The number of the beast is 666 by William Blake
^ MASPV 2003 - PGN
^ MASPV 2003 photos

What links here?

Page	Date Edited
Bestia	Jan 5, 2013
Engines	Mar 10, 2018
George Lyapko	Jan 14, 2013
Hungarian Chessprogram Open	Jan 6, 2013
MASPV 2001	Jan 9, 2013
MASPV 2003	Jan 9, 2013
MASPV 2007	May 5, 2013
Ufim	Mar 22, 2014

Up one level

Betsy

GerdIsenberg — Mon, 28 Jul 2014 09:11:04 GMT

Home * Engines * Betsy

		Betsy, a WinBoard compatible chess engine written by Landon W. Rabern in C with a little Assembly, first released in September 2000 ^[1]. Originally written in Pascal with its own text interface it was rewritten in C using rotated bitboards. Betsy applies PVS with null move pruning, and various standard and some aggressive non-standard extensions and reductions. According to the Arena site, Betsy was the first published chess engine able to play Chess960, and is therefor Arena partner engine ^[2].
Hurricane Betsy ^[3]

Forum Posts

Betsy 5.0 is now winboard compatable by Landon W. Rabern, CCC, September 06, 2000
Betsy 5.26 by Landon W. Rabern, CCC,
Betsy in Arena by Mark Loftus, CCC, September 13, 2003
Betsy 6.5.1 by Landon Rabern by Norbert Raimund Leisner, CCC, August 21, 2008

External Links

Chess Engine

Arena Chess GUI 3.5 - Betsy
Index of /chess/engines/Norbert's Collection/Betsy by Norbert Raimund Leisner, hosted by Kirill Kryukov
Betsy from WBEC Ridderkerk
Betsy 6.51 Nobook in CCRL 40/4
Betsy Fischer in CCRL 40/4 FRC

Misc

References

^ Betsy from WBEC Ridderkerk
^ Arena Chess GUI 3.5 - Betsy
^ Hurricane Betsy in the Gulf of Mexico in September of 1965 as taken by the TIROS-8 weather satellite. Source: NOAA Photo Library, September 4, 1965

What links here?

Page	Date Edited
Arena	Mar 16, 2018
Betsy	Jul 28, 2014
Engines	Mar 10, 2018

Up one Level

BlackBishop

GerdIsenberg — Fri, 07 Nov 2014 21:19:37 GMT

Home * Engines * BlackBishop

		BlackBishop, a free Chess Engine Communication Protocol and UCI compatible chess engine by Andreas Herrmann written in Delphi, first released in April 2004 ^[1]. BlackBishop evolved from his former engine Holmes , and applies NegaScout with null move and futility pruning, and lazy evaluation, maintains Attack tables for king safety and other evaluations, and performs move generation with the help of piece tables. BlackBishop was most active in 2004, playing the IPCCC 2004 and CCT6.
Black Bishop ^[2]

Forum Posts

perpetual check recognition by Andreas Herrmann, CCC, January 30, 2004 » Repetitions
BlackBishop 0.35 by Andreas Herrmann, Winboard Forum, November 04, 2006
BlackBishop 0.470 by Andreas Herrmann, Winboard Forum, November 13, 2006
BlackBishop 1.0 by Andreas Herrmann, Winboard Forum, June 07, 2009

External Links

Chess Engine

Misc

Black Bishop (disambiguation) from Wikipedia

References

^ BlackBishop from WBEC Ridderkerk
^ Illustration of Euplectes gierowii ansorgei by J. G. Keulemans (1899), Black Bishop from Wikipedia

What links here?

Page	Date Edited
Andreas Herrmann	Nov 7, 2014
BlackBishop	Nov 7, 2014
CCT6	May 29, 2014
Eigenmann Endgame Test	Jun 1, 2017
Engines	Mar 10, 2018
Holmes	Apr 24, 2014
Influence Quantity of Pieces	Jul 21, 2017
IPCCC 2004	Dec 1, 2014

Up one Level

Bobby

GerdIsenberg — Thu, 07 Jan 2016 15:03:15 GMT

Photos & Games

Mephisto

Sun Phoenix

Strategic Quiescence Search

Home * Engines * Bobby

Bobby,
a chess program by Hans-Joachim Kraas and Günther Schrüfer, competing at various World Computer- and World Microcomputer Chess Championships from 1983 until 1995 ^[1] . Bobby had a strong WCCC 1986 in Cologne, Germany, defeating the later Champion Cray Blitz in round two, with some chances to tie first place until the last round loss against Schaeffer's Sun Phoenix ^[2] . In 1993, Bobby II won the 3rd International Paderborn Computer Chess Championship.

The development of Bobby started in 1982 as part of Kraas' and Schrüfer's MSc thesis. It was written entirely in Pascal on the IBM 4341-2 ^[3] of the TU Braunschweig. In 1987 Bobby II was a complete redesign in C on a Atari ST microcomputer. A commercial successor of Bobby II is the program Doctor?, market by ChessBase as 16-bit engine in 1995 as analysis engine for ChessBase/Windows 1.0, and in 1998 as 32-bit add-on engine of the Fritz 5.32 package ^[4] ^[5]. According to Das große Computerschachbuch. ^[6] , Bobby had a sophisticated evaluation, with respect to king safety and passed pawns. Bobby's search was a STC-Search (solution tree cost oriented search) ^[7] , as elaborated in Schrüfer's 1988 PhD thesis ^[8]

Photos & Games

Mephisto

Günther Schrüfer, Hans-Joachim Kraas, Ossi Weiner and Richard Lang ^[9]

WCCC 1986, round 4, Bobby - Mephisto X ^[10]

[Event "WCCC 1986"]
[Site "Cologne, Germany"]
[Date "1986.06.14"]
[Round "4"]
[White "Bobby"]
[Black "Mephisto X"]
[Result "1-0"]
 
1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. c4 Nb6 5. exd6 exd6 6. Nc3 Be7 7. h3 O-O 
8. Nf3 Nc6 9. Be2 Bf5 10. O-O Qd7 11. Bf4 Rae8 12. a4 Bf6 13. a5 Nc8 14. a6 
b6 15. g4 Bxg4 16. hxg4 Qxg4+ 17. Bg3 Nxd4 18. Nxd4 Qxd4 19. Qc2 h6 20. Rfd1 
Qc5 21. Nb5 Be5 22. Rd5 Qc6 23. Bxe5 Rxe5 24. Rxe5 dxe5 25. Bg4 Nd6 26. Nxa7 
Qc5 27. Bd7 e4 28. Nb5 Nxb5 29. Bxb5 Qg5+ 30. Kf1 Qh4 31. Rd1 Qh1+ 32. Ke2 
Qf3+ 33. Ke1 Qh1+ 34. Kd2 Qg2 35. Kc1 Qg6 36. Qb3 c6 37. Ba4 c5 38. Qg3 Ra8
39. Qxg6 fxg6 40. Bb5 g5 41. Rd7 h5 42. a7 e3 43. fxe3 Rf8 44. Bc6 h4 
45. a8=Q Rxa8 46. Bxa8 h3 47. Rd5 1-0

Sun Phoenix

WCCC 1986, round 5, Vlastimil Hort, Frans Morsch, Hans van der Zijden, Hans-Joachim Kraas ^[11]

WCCC 1986, round 5, Bobby - Sun Phoenix

[Event "WCCC 1986"]
[Site "Cologne, Germany"]
[Date "1986.06.15"]
[Round "5"]
[White "Bobby"]
[Black "Sun Phoenix"]
[Result "0-1"]
 
1. e4 e6 2. b3 d5 3. Bb2 dxe4 4. Nc3 Nf6 5. Qe2 Be7 6. O-O-O Qd4 7. Re1 O-O 
8. Nxe4 Qxe4 9. Qxe4 Nxe4 10. Rxe4 Nd7 11. Nf3 Bc5 12. d4 Nf6 13. Rh4 Be7 
14. Kb1 e5 15. h3 e4 16. Ne5 Be6 17. Bc4 Bxc4 18. bxc4 c5 19. d5 e3 20. Rf4 
exf2 21. Rxf2 Ne4 22. Rf4 Nd2+ 23. Ka1 Bd6 24. Re1 Rae8 25. Re2 f5 26. Rh4 Ne4 
27. Nd3 Re7 28. Re3 g6 29. Nc1 Rfe8 30. a4 h5 31. Nb3 Kh7 32. Na5 Kh6 33. Rf3 
Ng3 34. Rb3 b6 35. Nc6 Re1+ 36. Ka2 g5 37. Nxa7 Ra8 38. Nb5 Rxa4+ 39. Ba3 Be5 
40. Nd4 0-1

Strategic Quiescence Search

Bobby applied a so called Strategic Quiescence Search as described in a 1989 ICCA Journal paper by Günther Schrüfer ^[12]. Schrüfer claimed the inclusion of certain none tactical moves in quiescence search an improvement over a pure tactical search in Bobby. He also stated, for some programs it might be a significant speed penalty in the number of moves searched per second to do so, i.e. in generating quiet moves. In Bobby this was irrelevant, since many of the values required have been precomputed for each node in any case. Beside the standard standing pat forward pruning conditions FP1 and FP2, all successors, not only captures, promotions and checks, were tested versus the forward pruning condition FP3.

Pseudo Code

int StategicQS(CNode n, int α, int ß) {
   int bestval = eval(n);
   if ( bestval >= ß ) return bestval;   // FP1, fail soft
   if ( bestval >  α ) α = bestval;      // FP2
   for all n´€ SUCC(n) do {              // search loop
      if ( evalPlus(n´) > α ) {          // FP3
         int actval = -StategicQS(n´, -ß, -α);
         if ( actval > bestval ) {
            bestval = actval;
            if ( bestval >= ß ) return bestval;
            if ( bestval >  α ) α = bestval;
         }
      }
      else if ( evalPlus(n´) > bestval ) bestval = evalPlus(n´);
   }
   return bestval;
}

Eval+

The evalPlus value is +oo in case of checking moves near the horizon, but scaled to zero for deeper searches to avoid "infinite" checks and search explosion. Otherwise evalPlus is incrementally calculated by eval(n) and move properties. In case of tactical moves, the sum of eval(n) and the value of a captured and/or promoted piece and a constant representing half the value of a Pawn is taken. For quiet or strategical moves, evalPlus relies on maximum score differences of two consecutive evaluations n´ and n, triggered by history success counters:

if ( isCheck ) 
   return infiniteIfNearBelowHorizon(depth);
if ( isCapture && isPromotion ) 
   return eval(n) - VALUE_PAWN/2 + Value(captured piece) + Value(promoted piece);
if ( isCapture )
   return eval(n) + VALUE_PAWN/2 + Value(captured piece);
if ( isPromotion )
   return eval(n) - VALUE_PAWN/2 + Value(promoted piece);
return eval(n) + hist[from][to].diff;

History Update

Positive history based success counters are associated with the maximum difference of two consecutive evaluations n´ and n found so far, while zero saturated counters also have zero difference and are therefor always pruned by FP3. Following scheme is used to update the butterfly boards:

   for all n´€ SUCC(n) do {
      int actval = -search(n´, -ß, -α);
      ...
      if ( none tactical ) {
         // History update by quiet move n -> n´
         if ( eval(n´) > eval(n) && actval > eval(n) ) {
            hist[from][to].success += 10;
            if ( eval(n´) - eval(n) > hist[from][to].diff )
               hist[from][to].diff = eval(n´) - eval(n);
         }
         else if ( entry.success > 0 ) {
            hist[from][to].success--;
            if ( hist[from][to].success == 0 ) hist[from][to].diff = 0;
         }
      }
      ...
   }

Publications

Rainer Bartel, Hans-Joachim Kraas, Günther Schrüfer (1985). Das große Computerschachbuch. Data Becker, Düsseldorf, ISBN 3-89011-117-3 (German), from amazon.de
Günther Schrüfer (1988). Minimax-Suchen : Kosten, Qualität und Algorithmen. Braunschweig : Technische Universität. (German)
Günther Schrüfer (1989). A Strategic Quiescence Search. ICCA Journal, Vol. 12, No. 1, pp. 3-9.

External Links

References

^ Bobby's ICGA Tournaments
^ Helmut Horacek, (1986). The Fifth World Computer Chess Championship Cologne, 1986, Research Unit for Information Science and Artificial Intelligence, University of Hamburg, from Kings move Welcome to the 1989 AGT World Computer Chess Championship. pg 21, available as pdf reprint from The Computer History Museum
^ IBM Reference / Glossary
^ Fritz 5.32 - mehr als nur ein Update! by Peter Schreiner (German), Schachclub Leinzell
^ Doctor? 2.0 / Engine MacIntosh from Schachversand Niggemann
^ Rainer Bartel, Hans-Joachim Kraas, Günther Schrüfer (1985). Das große Computerschachbuch. Data Becker, Düsseldorf, ISBN 3-89011-117-3 (German), from amazon.de
^ Doctor? by Dr. Hans-Joachim Kraas and Dr. Gunther Schrüfer
^ Günther Schrüfer (1988). Minimax-Suchen : Kosten, Qualität und Algorithmen. Braunschweig : Technische Universität. (German)
^ László Lindner, A SZÁMÍTÓGÉPES SAKK KÉPEKBEN című melléklete - The pictures of the Beginning of Chess Computers
^ Cologne 1986, Chess, Round 4, Game 4
^ Image from Pierre Nolot (1986). Echecs: Les Progès des Programmes. Jeux et Stratégie
^ Günther Schrüfer (1989). A Strategic Quiescence Search. ICCA Journal, Vol. 12, No. 1, pp. 3-9

What links here?

Page	Date Edited
ACM 1985	Jun 21, 2017
AMDAHL 470	Jul 19, 2016
Bernie	Oct 31, 2015
Bobby	Jan 7, 2016
Butterfly Boards	Jan 27, 2015
Doctor?	Jun 7, 2016
Engines	Mar 10, 2018
Fischerle	Aug 21, 2017
Günther Schrüfer	Jan 7, 2016
Hans-Joachim Kraas	Jan 7, 2016
History Leaf Pruning	Apr 15, 2013
IBM 370	Jan 20, 2018
IPCCC	Jan 20, 2017
IPCCC 1991	Jun 9, 2016
IPCCC 1993	Nov 1, 2016
IPCCC 1994	Jul 31, 2013
King Pawn Tropism	Sep 1, 2014
Late Move Reductions	Sep 25, 2017
Nona	Jan 7, 2016
Pruning	Jan 1, 2018
Quiescence Search	Aug 19, 2017
Relative History Heuristic	Jun 8, 2015
Selectivity	Jan 12, 2018
Shy	Jul 19, 2016
Strategy	Jan 18, 2018
WCCC 1983	Jan 20, 2018
WCCC 1986	Jul 27, 2017
WMCCC 1993	Dec 30, 2017
WMCCC 1995	Jan 3, 2018

Up one Level

Centaur

GerdIsenberg — Fri, 24 Mar 2017 19:28:28 GMT

Home * Engines * Centaur

		Centaur (Russian: Кентавр), a chess program by primary author Victor Vikhrev and Alexey Manjakhin. Centaur won the First Soviet Computer-Chess Championship 1988 in Ulan-Ude, and further competed at the First International Chess-Computer Tournament in the USSR 1989 in Moscow, at three World Computer Chess Championships, the WCCC 1989 in Edmonton, the WCCC 1992 in Madrid, and the WCCC 1999 in Paderborn, four World Microcomputer Chess Championships ^[1] , two Uniform-Platform Computer Chess Championships, and three Aegon Man-Machine Tournaments ^[2] ^[3] ^[4]. Centaur, along with some code units incorporated from Mirage by Vladimir Rybinkin and Yuri Shpeer, further evolved to the Dragon analysis engine of Convekta's Chess Assistant database ^[5], not to confused with the original Dragon engine by Yuri Shpeer ^[6].
Sandro Botticelli, Pallas and Centaur, 1482 ^[7]

Screenshot

Centaur Screen ^[8]

Photos & Games

WCCC 1999: Centaur vs. Mini, Victor Vikhrev and Harald Prokop

[Event "WCCC 1999"]
[Site "Paderborn, Germany"]
[Date "1999.06.19"]
[Round "7"]
[White "Centaur"]
[Black "Mini"]
[Result "0-1"]
 
1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Nc6 7.O-O Be7 8.Re1 Bg4 9.c4 Nf6
10.cxd5 Bxf3 11.Qxf3 Qxd5 12.Qxd5 Nxd5 13.Nc3 Ndb4 14.Be4 Nxd4 15.Bf4 Ne6 16.a3 Nd3
17.Bxd3 Nxf4 18.Bf5 Kf8 19.Rad1 g6 20.Be4 Ne621.Bd5 Nd8 22.Re2 c6 23.Bc4 b5 24.Bb3 f5
25.Rd7 Bf6 26.a4 a6 27.h3 Rb8 28.Red2 Bg5 29.f4 Bf6 30.axb5 axb5 31.Kh2 Ke8 32.Rc7 h5
33.Rd6 Rf8 34.Nd1 Rb6 35.g3 Rb8 36.Rh7 c5 37.Bd5 c4 38.Rh6 Ke7 39.Ra6 Rc8 40.Rxg6 h4
41.gxh4 Rc5 42.Ra7+ Kd6 43.Bg2 Ne6 44.Kg3 b4 45.Ne3 c3 46.Ra6+ Kd7 47.Bd5 Nc7 48.Rgxf6 
Rxf6 49.Rxf6 Nxd5 50.bxc3 Nxf6 51.cxb4 Rc3 52.Kf2 Ke6 53.b5 Rb3 54.Nc4 Nh5 55.Nd2 Rxb5 
56.Nf3 Rb2+ 57.Ke3 Rb3+ 58.Kf2 Kd5 59.Ng5 Nxf4 60.Nf3 Nxh3+ 61.Ke2 f4 62.Nd2 Re3+ 63.Kd1 
Nf2+ 64.Kc1 Ne4 65.h5 Re1+ 66.Kb2 Re2 67.Kb3 Nxd2+ 68.Kb2 Kc4 69.h6 Nb3+ 70.Ka3 Nc1 
71.Ka4 0-1

Descriptions

1989

based on the WCCC 1989 booklet ^[9] :

Centauer is a new chess-playing program with the heuristic search to consider the decisive series of moves. The algorithms is based on the probability logic and uses a fuzzy value of positions. The depth of the search is not limited. The whole information about all the series of moves is kept in RAM and is used to determine the decisive series of moves. Centaur features a low number of position analyzed. This is compensated with thoroughness of the position evaluation.

1991

from Don Beal's WMCCC 1991 report ^[10] :

`Centaur is the outstanding exception in the current pattern. It uses a much more human like approach, and despite its eventual losses, actually played well most of the time. For instance, it had a draw against Gideon for a long time, only going astray in the endgame.`

Written by Victor Vikhrev and Alexey Manjakhin, and winner of the first Moscow computer-chess tournament, this program is highly unconventional, and does not use alpha-beta, iterative search. Instead, it grows a selective tree, kept fully in memory, on a best-first basis. Position evaluation is not reduced to one number - instead a vector of values is produced from which 3 optimistic and 3 pessimistic evaluations are made under different assumptions. These 6 values determine a probability distribution of results for a position, which is used to guide tree growth and ultimately to choose a move. Victor Vikhrev describes his approach as intermediate between conventional programs and the even more selective approach of Botvinnik's program, Pioneer.

Centaur is the outstanding exception in the current pattern. It uses a much more human like approach, and despite its eventual losses, actually played well most of the time. For instance, it had a draw against Gideon for a long time, only going astray in the endgame.

Written by Victor Vikhrev and Alexey Manjakhin, and winner of the first Moscow computer-chess tournament, this program is highly unconventional, and does not use alpha-beta, iterative search. Instead, it grows a selective tree, kept fully in memory, on a best-first basis. Position evaluation is not reduced to one number - instead a vector of values is produced from which 3 optimistic and 3 pessimistic evaluations are made under different assumptions. These 6 values determine a probability distribution of results for a position, which is used to guide tree growth and ultimately to choose a move. Victor Vikhrev describes his approach as intermediate between conventional programs and the even more selective approach of Botvinnik's program, Pioneer.

1993

from Don Beal's UPCCC 1993 report ^[11] ^[12] :

Written by Victor Vikrev, a nuclear physicist in Moscow, as a major hobby over the past 30 years, plus Alexei Manjakhin. It is remarkable for being very different in design from all the other programs that do well in championships. It explores only a few future positions (instead of millions), but analyses them in more detail. In this respect its thinking is more human-like than any other program. It scored 2 from 5 in the last "unlimited machine" championship, and placed 17.

1999

from the ICGA-site ^[13] :

Centaur is a highly selective program, originated from Kurchatov Institute in Moscow. It is a completely unique program. Despite the lighting speed of its hardware it only examines about 500 positions per second. Centaur has a rating of 2,266 at AEGON97.

Centaur uses 5 values for estimation of chess position (one realistic, two pessimistic and two optimistic). All 5 values of a position are saved in memory of computer and are used for choice of direction of investigation of position.

Last modification of Centaur uses some code units from program Mirage, which is made in Russia. Principles of Centaur are described in ICCA Journal 1996, 2 ^[14]

Publications

Victor Vikhrev (1996) The Choice of a Research Direction. ICCA Journal, Vol. 19, No. 2

Forum Posts

QMW computer chess by Don Beal, rec.games.chess, August 19, 1993 » UPCCC 1993
Re: La Máquina Preservadora. Programas de Ajedrez by Tibono, Meca Foro, October 09, 2015 (Spanish)
Centaur by Fernando, Hiarcs Forum, March 16, 2017

External Links

Centaur's ICGA Tournaments
Кентавр (Russian)
Centaur, translated by Google Translate
Download Chess Programs hosted by Ed Schröder
Advanced Chess from Wikipedia (Centaur chess)
Centaur (disambiguation) from Wikipedia
Centaur from Wikipedia (Greek mythology)

References

^ Centaur's ICGA Tournaments
^ CSVN Aegon 1995 site
^ CSVN Aegon 1996 site
^ CSVN Aegon 1997 site
^ Chess Assistant - ChessOK
^ Заставить работать машину клиента! [20] - Конференция iXBT.com, September 01, 2009
^ Renaissance Art - The Renaissance in Florence: Republican and Medici (15th c.)
^ Septober - Computerschach by Herbert Marquardt
^ Kings Move - Welcome to the 1989 AGT World Computer Chess Championship. Edmonton, Alberta, Canada, Courtesy of Peter Jennings, from The Computer History Museum, pdf
^ Don Beal (1991). Report on the 11th World Microcomputer Chess Championship. ICCA Journal, Vol. 14, No. 2
^ Don Beal (1993). Report on the QMW 1993 Uniform-Platform Computer-Chess Championship. ICCA Journal, Vol. 16, No. 3
^ QMW computer chess by Don Beal, rec.games.chess, August 19, 1993
^ Centaur's ICGA Tournaments
^ Victor Vikhrev (1996) The Choice of a Research Direction. ICCA Journal, Vol. 19, No. 2

What links here?

Page	Date Edited
Aegon 1995	Apr 6, 2017
Aegon 1996	Jan 22, 2017
Aegon 1997	Apr 7, 2017
Alexey Manjakhin	Jan 7, 2016
Algir	Feb 17, 2013
Centaur	Mar 24, 2017
Cheiron	Jan 7, 2016
Chiron	Sep 24, 2017
Dragon (Chess Assistant)	Jul 30, 2013
Dragon RU	Jan 8, 2016
Elektronika IM	Nov 30, 2017
Engines	Mar 10, 2018
First International Chess-Computer Tournament in the USSR 1989	Apr 22, 2018
First Soviet Computer-Chess Championship 1988	Dec 7, 2016
Innovation	Jun 12, 2016
Mini	Jan 7, 2016
Mirage	Jul 12, 2016
Strategist	Jun 13, 2013
UPCCC 1993	Mar 6, 2015
UPCCC 1994	Mar 9, 2012
Victor Vikhrev	Jan 7, 2016
WCCC 1989	Dec 5, 2017
WCCC 1992	Feb 26, 2018
WCCC 1999	Jul 13, 2017
WMCCC 1991	Sep 18, 2016
WMCCC 1993	Dec 30, 2017
WMCCC 1995	Jan 3, 2018
WMCCC 1996	Sep 15, 2016

Up one Level

Chat

GerdIsenberg — Thu, 07 Jan 2016 16:02:47 GMT

Home * Engines * Chat

		Chat, Wolfgang Delmare's first chess program, playing the WCCC 1986, WMCCC 1987 and WMCCC 1988 ^[1]. Chat was written in Pascal, typically running as DOS engine with a command line interface, at the WCCC 1986 on a CDC Cyper 175, at the WMCCC 1988 as dedicated unit on a 68020 processor with a SciSys Leonardo board ^[2] ^[3] as user interface ^[4] ^[5] . According to Thorsten Czub, Chat had only a brute-force search depth of one ply, but was otherwise quite selective ^[6] .
Whinchat ^[7]

Selected Games

WCCC 1986, round 4, Chat - Enterprise, ..., Wolfgang Delmare (white shirt) ^[8] ^[9]

[Event "WCCC 1986"]
[Site "Cologne, FRG"]
[Date "1986.06.14"]
[Round "4"]
[White "Chat"]
[Black "Enterprise"]
[Result "1/2-1/2"]
 
1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 c5 6.Nf3 Nc6 7.Bd2 cxd4 8.exd4 d5 
9.c5 Bxc3 10.Bxc3 Ne4 11.Qc2 f5 12.O-O Qc7 13.Kh1 Rf6 14.b4 Rh6 15.b5 Ne7 
16.Bb4 Ng6 17.c6 Nf4 18.cxb7 Qxb7 19.g3 Nxd3 20.Qxd3 a6 21.a4 axb5 22.Qxb5 
Qxb5 23.axb5 Rxa1 24.Rxa1 Nxf2+ 25.Kg2 Nd3 26.Bd2 Rf6 27.Rb1 e5 28.Nxe5 Nxe5 
29.dxe5 Rf7 30.Rc1 Rf8 31.Rc7 d4 32.Re7 d3 33.b6 Ba6 34.Ra7 Bb5 35.Kf3 Bc6+ 
36.Kf4 Rb8 37.Ba5 Rd8 38.Bd2 g6 39.Ke3 Rc8 40.Bc3 Be4 41.Rc7 Rb8 42.e6 Kf8 
43.Bg7+ Ke8 44.Bd4 h6 45.Rg7 d2 46.Rg8+ Ke7 47.Rg7+ Kxe6 48.Kxd2 Kd5 49.Bf2 
g5 50.Rh7 f4 51.Rxh6 Rd8 52.Ke1 Bf3 53.Rh7 Re8+ 54.Kf1 Be2+ 55.Kg1 Ke6 56.Rg7 
Kf6 57.Bd4+ Kf5 58.Kf2 Bd1 59.Rf7+ Ke6 60.Rc7 Kd6 61.Bc5+ Kd5 62.Be7 fxg3+ 
63.Kxg3 Ra8 64.b7 Ba4 65.Rc5+ Ke6 66.Rc7 Kd5 67.Rc5+ Ke6 68.Rc7 Kd5 1/2-1/2

External Links

References

^ Chat's ICGA Tournaments
^ Leonardo from Chess Computer UK by Mike Watters
^ SciSys Leonardo from Schachcomputer.info Wiki
^ Hans-Peter Ketterling (1989). Computerschachneuheiten auf der Nürnberger Spielwarenmesse (Teil 3 und 4). Europa-Rochade 03-1989, 04-1989,
pdf hosted by Hein Veldhuis
^ Re: One ply chess engine by Thorsten Czub, CCC, August 23, 2011
^ Re: One ply chess engine by Thorsten Czub, CCC, August 23, 2011
^ Saxicola rubetra by Marek Szczepanek, CC BY-SA 3.0, Wikimedia Commons, Chat (bird) from Wikipedia
^ WCCC 1986 Video 0:31
^ Cologne 1986 - Chess - Round 4 - Game 2 (ICGA Tournaments)

What links here?

Page	Date Edited
CDC Cyber	Dec 22, 2017
Chat	Jan 7, 2016
Engines	Mar 10, 2018
Enterprise	Jun 23, 2017
Vaxchess	Jan 7, 2016
WCCC 1986	Jul 27, 2017
WMCCC 1987	Jan 7, 2016
WMCCC 1988	Oct 27, 2016
Wolfgang Delmare	Jan 25, 2016

Up one Level

Chaturanga

GerdIsenberg — Thu, 04 Apr 2013 13:17:49 GMT

Home * Engines * Chaturanga

		Chaturanga, a chess program by John Poduska, Jr. written in Pascal. In 1981 it searched about 1000 Nodes per second on a 68000 based Apollo workstation ^[1] . It competed twice at ACM North American Computer Chess Championships, ACM 1981 and ACM 1982. The name Chaturanga was derived from the ancient Indian game which is presumed to be the common ancestor of the games of Chess, Shogi and Chinese Chess ^[2] .
Krishna and Radha playing Chaturanga on an 8x8 Ashtāpada ^[3] ^[4]

Namesake

Chaturanga by Stefano Malloggi

External Links

References

What links here?

Page	Date Edited
ACM 1981	Jan 19, 2018
ACM 1982	Jul 19, 2016
Chaturanga	Apr 4, 2013
Chaturanga IT	Jan 7, 2016
Engines	Mar 10, 2018
IGWT 2013	Jun 23, 2014
John Poduska, Jr.	Aug 2, 2016

Up one level

Chess 0.5

GerdIsenberg — Sun, 20 Nov 2016 17:11:00 GMT

Home * Engines * Chess 0.5

		Chess 0.5, a program by Larry Atkin and Peter W. Frey for didactic purposes, written in the ETH Zurich dialect of Pascal for the CDC 6600 series of mainframes, published 1978/1979 in Byte Magazine, and re-published on-line in 2005, available from Scott A. Moore's ^[1] sites, unfortunately with some OCR-errors such as syntactical correct replacement of '*' by '+' with score factor by side (XTMV, ±1) in some places ^[2] . Chess 0.5 may be compiled with GNU Pascal for recent hardware. Due to non-local goto statements over procedure or function boundaries compiling with Free Pascal is not possible ^[3] . Larry Atkin is co-author of the famous Northwestern University Chess line of programs. At the time of the article, Chess was at about version 4.6 ^[4] . Chess 0.5 is based on his intimate knowledge of that program, but is a seperate program designed for pedagogical purposes to play chess vaguely well ^[5] using Chess 4.x like structures of a Shannon Type A approach with alpha-beta and quiescence search, bitboards and incremental updated attack tables.
BYTE, Vol. 3, No. 10 ^[6]

Blueprint

Description

Board Representation

Bitboard Infrastructure

Blueprint

As encouraged by Frey and Atkin in their article "The reader with an interest in chess and programming should use this listing as starting point for developing a program" ^[7] , Chess 0.5 was origin of at least three other competing programs, the Austrian Merlin by Hermann Kaindl, Helmut Horacek, Marcus Wagner and Roland Schreier, further developed in Pascal except some time critical, often called routines, which were re-written in CDC assembly by Wagner ^[8] ^[9] , the Dutch Chess 0.5X by Wim Elsenaar, a PDP-11 assembly port, and according to postings in rgcc ^[10] , the Finnish Shy by Juha Kasanen, Mika Korhonen and Timo Saari, written in Algol.

Description

Board Representation

Chess 0.5 keeps an 8x8 board either indexed by square or rank and file, ...

CONST
  AX = 0;       ZX = 31;               (* SUBSETS OF SQUARES *)
  AS = 0;       ZS = 63;               (* BOARD VECTOR LIMITS *)
TYPE
  TF = (F1,F2,F3,F4,F5,F6,F7,F8);      (* FILES *)
  TR = (R1,R2,R3,R4,R5,R6,R7,R8);      (* RANKS *)
  TI = INTEGER;                        (* NUMBERS *)
  TS = AS..ZS;                         (* SQUARES *)
  TX = AX..ZX;                         (* SOME SQUARES *)
  TY = AY..ZY;                         (* NUMBER OF TX'S IN A BOARD *)
  TM = (LITE,DARK,NONE);               (* SIDES *)
  TP = (LP,LR,LN,LB,LQ,LK,DP,DR,DN,DB,DQ,DK,MT); (* PIECES: LIGHT PAWN,... , DARK KING, EMPTY SQUARE *)
  SX = SET OF TX;                      (* SET OF SOME SQUARES *)
 
  RB = RECORD                          (*   BOARDS  *)
    RBTM : TM;                         (*  SIDE  TO MOVE  *)
    RBTS : TT;                         (*  ENPASSANT  SQUARE   *)
    RBTI : TI;                         (*  MOVE   NUMBER   *)
    RBSQ : SQ;                         (*  CASTLE  FLAGS   *)
    CASE INTEGER OF
      0: ( RBIS  : ARRAY [TS] OF TP);   (* INDEXED BY SQUARE *)
      1: ( RBIRF : ARRAY [TR,TF] OF TP);(* INDEXED BY RANK AND FILE *)
    END;

... and further relies on bitboards, defined as union of arrays of sets and integers:

  RS = RECORD                          (* BIT BOARDS *)
    CASE INTEGER OF
      0: (RSSS: ARRAY [TY] OF SX);     (* ARRAY OF SETS *)
      1: (RSTI: ARRAY [TY] OF TI);     (* ARRAY OF INTEGERS *)
    END;

Beside the mailbox arrays (BOARD, MBORD) and bitboard board definition (TPLOC, TMLOC), Chess 0.5 maintains incremental updated attack tables, two 8x8 arrays ATKTO and ATKFR, the first for every square a attack bitboard to other squares of the piece (if any) residing on that square, the second for each square a bitboard of all white and black man attacking this square.

  BOARD : RB;                          (* THE BOARD *)
  MBORD : ARRAY [TS] OF TP;            (* LOOK-AHEAD BOARD *)
  ATKFR : ARRAY [TS] OF RS;            (* ATTACKS FROM A SQUARE *)
  ATKTO : ARRAY [TS] OF RS;            (* ATTACKS TO A SQUARE *)
  ALATK : ARRAY [TM] OF RS;            (* ATTACKS BY EACH COLOR *)
  TPLOC : ARRAY [TP] OF RS;            (* LOCATIONS OF PIECE BY TYPE *)
  TMLOC : ARRAY [TM] OF RS;            (* LOCATIONS OF PIECE BY COLOR *)

Bitboard Infrastructure

Setwise Operations

Bitboard intersection, union and relative complement are implemented with set-wise operations "*, +, -", complement (not) by relative complement from the universe ([AX..ZX]):

PROCEDURE ANDRS                        (* INTERSECTION OF TWO BITBOARDS *)
  (VAR C:RS;                           (* RESULT *)
   A, B:RS);                           (* OPERANDS *)
VAR
  INTY : TY;                           (* BIT BOARD WORD INDEX *)
BEGIN
  FOR INTY := AY TO ZY DO
    C.RSSS[INTY] := A.RSSS[INTY] * B.RSSS[INTY];
END;  (* ANDRS *)
 
PROCEDURE IORRS                        (* UNION OF TWO BIT BOARDS *)
 (VAR C:RS;                            (* RESULT *)
  A, B:RS);                            (* OPERANDS *)
VAR
  INTY : TY;                           (* BIT BOARD WORD INDEX *)
BEGIN
  FOR   INTY :=  AY TO ZY DO
    C.RSSS[INTY] := A.RSSS[INTY] + B.RSSS[INTY];
END;  (* IORRS *)
 
PROCEDURE NOTRS                        (* COMPLEMENT OF A BIT BOARD *)
 (VAR C:RS;                            (* RESULT *)
  A:RS);                               (* OPERAND *)
VAR
  INTY : TY;                           (* BIT BOARD WORD INDEX *)
BEGIN
  FOR INTY := AY TO ZY DO
    C.RSSS[INTY] := [AX..ZX] - A.RSSS[INTY];
END;  (* NOTRS *)

BitScan

BitScan reverse with reset is implemented with machine dependent CDC 6600 float conversion (omitted here) - the machine independent code inefficiently loops over up to 2*32 bits of the set and cries for improvement:

FUNCTION NXTTS                         (* NEXT ELEMENT IN BIT BOARD *)
 (VAR A:RS;                            (* BIT BOARD TO LOCATE FIRST SQUARE, AND THEN REMOVE *)
  VAR B:TS                             (* SQUARE NUMBER OF FIRST SQUARE IN BIT BOARD *)
 ): TB;                                (* TRUE IFF ANY SQUARES WERE SET INITIALLY *)
LABEL
  11;                                  (* RETURN *)
VAR
  INTX : TX;                           (* BIT BOARD BIT INDEX *)
  INTY : TY;                           (* BIT BOARD WORD INDEX *)
  X : RK;                              (* KLUDGE WORD *)
BEGIN
  FOR INTY := ZY DOWNTO AY DO          (* LOOP THRU BIT BOARD WORDS *)
    IF A.RSTI[INTY] <> 0 THEN
    BEGIN
      FOR INTX := ZX DOWNTO AX DO      (* LOOP THROUGH BITS IN WORD OF SET *)
        IF INTX IN  A.RSSS[INTY] THEN
        BEGIN
          B := INTX+INTY*(ZX+1);       (* RETURN SQUARE NUMBER *)
          A.RSSS[INTY] := A.RSSS[INTY] - [INTX]; (* REMOVE  BIT FROM WORD *)
          NXTTS := TRUE;               (* RETURN A BIT SET *)
          GOTO 11;                     (* RETURN *)
        END;
    END;
  NXTTS := FALSE;                      (* ELSE RETURN NC BITS SET *)
11:                                    (* RETURN *)
END;  (* NXTTS *)

Popcount

The machine independent population count relies on the above bitscan with reset!

FUNCTION CNTRS                         (* COUNT NENBERS OF A BIT BOARD *)
(A:RS): TS;                            (* BIT BOARD TO COUNT *)
VAR
  INTS : TS;                           (* TEMPORARY *)
  INRS : RS;                           (* SCRATCH *)
  IMTS : TS;                           (* SCRATCH *)
BEGIN
  INTS := 0;
  CPYRS(INRS,A);
  WHILE NXTTS(INRS,IMTS) DO
    INTS := INTS+1;                    (* COUNT SQUARES *)
  CNTRS := INTS;                       (* RETURN SUM *)
END;  (* CNTRS *)

Evaluation

Chess 0.5's evaluation routine EVALU8 implements a lazy evaluation only for too worse scores. If the incremental updated material balance plus the maximum positional score is still less or equal than alpha (best value two plies up BSTVL[JNTK-2]), only the material balance is assigned without further positional analysis. Otherwise EVALU8 consides piece mobility (counting attacks), pawn structure, king safety and some rook terms such as doubled rooks and rook on 7th rank. Differences of light minus dark positional terms are adjusted by appropriate feature weights. To make white point of view scores relative to the side to move, they are multiplied by a score factor (+1, -1) indexed by side.

PROCEDURE EVALU8;                      (* EVALUATE CURRENT POSITION *)
  FUNCTION EVKING                      (* EVALUATE KING *)
  FUNCTION EVMOBL                      (* EVALUATE MOBILITY *)
  FUNCTION EVPAWN                      (* EVALUATE PAWNS *)
  FUNCTION EVROOK                      (* EVALUATE ROOKS *)
BEGIN
  IF XTMV[JNTM]*MBVAL[JNTK] + MAXPS <= BSTVL[JNTK-2] THEN   (* !!! OCR  *)
                                       (* MOVE WILL PRUNE ANYWAY *)
    INTV := XTMV[JNTM] * MBVAL[JNTK]
  ELSE
  BEGIN
    INTV := (  FWPAWN*(EVPAWN(TPLOC[LP],S2,R2)-EVPAWN(TPLOC[DP],S4,R7))
             + FWMINM*(EVMOBL(LB,LN)          -EVMOBL(DB,DN)          )
             + FWMAJM*(EVMOBL(LR,LQ)          -EVMOBL(DR,DQ)          )
             + FWROOK*(EVROOK(TPLOC[LR],XRRS[R7])
                      -EVROOK(TPLOC[DR],XRRS[R2])                     )
             + FWKING*(EVKING(TPLOC[LK],TPLOC[LP])
                      -EVKING(TPLOC[DK],TPLOC[DP])                    )
            ) DIV 64;
    MAXPS := MAX(MAXPS,ABS(INTV));
    INTV := XTMV[JNTM] * (MBVAL[JNTK] + INTV);
  END;
  IF SWTR THEN
    BEGIN
      WRITE(" EVALU8",JNTK,JNTW,INDEX[JNTK],INTV);
      PRIMOV(MOVES[INDEX[JNTK]]);
    END;
  VALUE[INDEX[JNTK]] := INTV;          (* RETURN SCORE *)
END;  (* EVALU8 *)

Search

The search is implemented spaghetti like non-recursively as finite-state machine with goto labels using explicit stacks aka ply indexed arrays, and features iterative deepening with aspiration and alpha-beta pruning. The value array of best moves indexed by current ply is the current alpha of a newly entered node, initialized by grand parent's best value (ply-2) - best value of the parent node (ply-1) is minus beta in the negamax sense. The nested function SELECT implements a staged move generation, considering root search (ply 0), full-width and quiescence, generating captures in MVV/LVA order, killers, and remaining moves. While the ply indices range from 0 to 16, the best value array needs three additional sentinels due to ply-2, ply-1, and ply+1 accesses. The outline of the search routine with jump labels (:) is given below, most lines omitted:

  BSTVL : ARRAY [AKM2..ZKP1] OF TV;    (* VALUE OF BEST MOVE [-2..17] *)
 
FUNCTION SEARCH                        (* SEARCH LOOK-AHEAD TREE *)
: TW;                                  (* RETURNS THE BEST MOVE *)
  PROCEDURE NEWBST                     (* SAVE BEST MOVE INFORMATION *)
    (A:TK);                            (* PLY OF BEST MOVE *)
 
  FUNCTION MINMAX                      (* PERFORM MINIMAX OPERATION *)
    (A:TK)                             (* PLY TO MINIMAX AT *)
     : TB;                             (* TRUE IF REFUTATION *)
    MINMAX := FALSE;                   (* DEFAULT IS NO PRUNING *)
    IF -BSTVL[A+1] > BSTVL[A] THEN     (* Score > Alpha ? *)
    BEGIN
      BSTVL[A] := -BSTVL[A+1];         (* Alpha = Score  *)
      NEWBST(A);                       (* SAVE BEST MOVE *)
      MINMAX := BSTVL[A+1] <= BSTVL[A-1]; (* -Score < -Beta => Score > Beta *)
    END;
  END;  (* MINMAX *)
 
  FUNCTION SELECT                      (* SELECT NEXT MOVE TO SEARCH *)
     : TB;                             (* TRUE IF MOVE RETURNED *)
  BEGIN
  21:  (* NEW SEARCH MOOE *)
    CASE SRCHM[JNTK] OF
      H0:  (* INITIALIZE FOR NEW MOVE *)
      H1:  (* INITIALIZE AT  NEW DEPTH *)
      H2:  (* CAPTURE SEARCH *)
      H3:  (* FULL WIDTH SEARCH - CAPTURES *)
      H4:  (* INITIALIZE SCAN OF CASTLE MOVES AND OTHER MOVES BY KILLER PIECE *)
      H5:  (* FULL WIDTH SEARCH - CASTLES AND OTHER MOVES BY KILLER PIECE *)
      H6:  (* FULL WIDTH SEARCH - REMAINING MOVES *)
      H7:  (* RESEARCH FIRST PLY *)
  22:  (* SELECT EXIT *)
    SELECT := INTB;                    (* RETURN VALUE *)
  END;  (* SELECT *)
 
BEGIN  (* SEARCH *)
  EVALU8;                              (* INITIAL GUESS AT SCORE *)
  BSTVL[AK-2] :=   VALUE[AW] - WINDOW; (* INITIALIZE ALPHA-BETA WINDON *)
  BSTVL[AK-1] := -(VALUE[AW] + WINDOW);
  JMTK := AK+1;
  WHILE (NODES < FNODEL) AND (JNTK < MAX(ZK DIV 2, ZK-8)) DO
  BEGIN
11:  (* START NEW PLY *)
12:  (* DIFFERENT  FIRST MOVE  *)
13:  (* FLOAT   VALUE   BACK  *)
      IF   MINMAX(JNTK)   THEN
        GOTO 15;                       (* PRUNE *)
14:  (* FIND ANOTHER MOVE AT THIS PLY *)
15:  (* BACK UP A PLY *)
16:  (* EXIT SEARCH *)
  SEARCH := BSTMV[AK];                 (* RETURN BEST MOVE *)
END;  (* SEARCH *)

Publications

Peter W. Frey, Larry Atkin (1978). Creating a Chess Player. An Essay on Human and Computer Chess Skill, BYTE, Vol. 3, No. 10, pp. 182-191. pdf from The Computer History Museum
Peter W. Frey, Larry Atkin (1978). Creating a Chess Player, Part 2: Chess 0.5. BYTE, Vol. 3, No. 11
Peter W. Frey, Larry Atkin (1978). Creating a Chess Player, Part 3: Chess 0.5 (continued). BYTE, Vol. 3, No. 12
Peter W. Frey, Larry Atkin (1979). Creating a Chess-Player, Part 4: Thoughts on Strategy. In Blaise W. Liffick (ed.), The Byte Book of Pascal, pp. 143-155. Byte Publications, also BYTE, Vol. 4, No. 1

Forum Posts

Byte Chess 0.5 finally available. From Byte Magazine 1978 by I Forget, rgcc, June 01, 2005
Update for Byte Chess 0.5 by I Forget, comp.lang.pascal.misc, June 12, 2005
Need a little help from a Pascal guru (Chess05 Frey/Atkin) by Jim Ablett, CCC, January 09, 2012

External Links

Chess 0.5, Release 1 - 2005-05-30 by Scott A. Moore
Byte Chess 0.5 source code hosted by Scott A. Moore
Classic Computer Chess - ... The programs of yesteryear by Carey, hosted by the Internet Archive
Computer-Schach by Andre Adrian (German)
Chess05GNU.pas

References

^ Scott A. Moore's site
^ Byte Chess 0.5 source code (OCR-Errors!)
^ Re: Need a little help from a Pascal guru (Chess05 Frey/Atkin) by Steven Edwards, CCC, January 09, 2012
^ Chess 4.6 source code, gift of David Slate, from The Computer History Museum, pdf
^ Chess 0.5, Release 1 - 2005-05-30
^ Byte Vol. 3, No. 10, October 1978 from the Internet Archive
^ Peter W. Frey, Larry Atkin (1978). Creating a Chess Player, Part 3: Chess 0.5 (continued). BYTE, Vol. 3, No. 12
^ Werner DePauli-Schimanovich (2006). Europolis 6. Informatik für Spiele und Verkehr. Extension der Mengenlehre, Herausgeber: Franz Pichler, Universitätsverlag Rudolf Trauner, ISBN 978-3-85487-946-6, (SG7) Merlin (ein ComputerChess-Programm) s. 171 (German), Google Books
^ Helmut Horacek, Marcus Wagner (1981). Das Schachprogramm Merlin, Verbesserung von Laufzeit-Effizient, Eröffnungsbibliothek und Bewertungsfunktion. 4. Tagung "Berichte aus Informatik-Instituten" (German)
^ Re: Byte Chess 0.5 finally available. From Byte Magazine 1978 by I Forget, rgcc, June 02, 2005

What links here?

Page	Date Edited
BitScan	Sep 10, 2017
Byte Magazine	Nov 20, 2016
CDC 6600	Oct 8, 2014
Chess	Jan 21, 2018
Chess (Program)	Dec 22, 2017
Chess 0.5	Nov 20, 2016
Chess 0.5X	Nov 5, 2015
Chess 2013	Nov 6, 2013
Chess 7.0	Jul 13, 2015
CookieCat	Nov 15, 2016
Engines	Mar 10, 2018
Larry Atkin	Jan 7, 2016
Marcus Wagner	Jan 7, 2016
Merlin	Jan 20, 2018
Northwestern University	Sep 5, 2017
Pascal	Nov 28, 2016
Peter W. Frey	Dec 25, 2017
Shy	Jul 19, 2016

Up one Level

CookieCat

GerdIsenberg — Tue, 15 Nov 2016 10:56:17 GMT

Home * Engines * CookieCat

		CookieCat, an educational open source chess program by Steven Edwards designed for pedagogical purposes, written in Free Pascal ^[1]. CookieCat evolved from the earlier Bozochess project ^[2] announced in October 2011 ^[3], renamed in December 2011 ^[4], and first released in January 2012 ^[5] under the permissive BSD License. However, Steven's wish that his CookieCat should be easily searchable on the net without too many false positives didn't fulfill when Steven Universe came up with a fictional character ^[6] and ice cream ^[7] in 2013.
Spooky ^[8]

Description

Bitboard Infrastructure

Description

CookieCat utilizes bitboards as basic data structure to represent the board. Inside CookieCat's source code ^[9], there are three groups of routines named after some of Steven's feline companions. There are the Lucky positional evaluator routines, the Smokey mate finder routines, and the Spooky general search routines. The names were chosen not so much to be cute, but rather to make it easier for others to identify the program's functional organization ^[10]. CookieCat features five hash-tables, beside the main transposition table, an endgame tablebase cache, a pawn hash table, evaluation hash table, and a dedicated perft hash table, and can further probe an opening book ^[11] and Edwards' tablebases.

Bitboard Infrastructure

Bitboards are defined as union (variable structure) of four 16-bit words and one 64 bit value:

    bbtype =
      record
        case Boolean of
          False: (wvec: array [bbwtype] of bbwspantype); { Array of bitboard words }
          True:  (bv64: ui64type)                        { Unsigned 64 bit value }
      end;

Population count and BitScan rely on 16-bit lookups:

  function BbCount(var bb: bbtype): cctype; inline;
    var
      myresult: cctype;
      bbw: bbwtype;
  begin
    with bb do
      begin
        myresult := 0;
        for bbw := bbwmin to bbwmax do
          myresult := myresult + bitcountvec[wvec[bbw]]
      end;
    BbCount := myresult
  end; { BbCount }
 
  function BbFirstSq(var bb: bbtype): sqxtype; inline;
    var
      myresult: sqxtype;
      bbwindex: Integer;
      wordfirstbit: Integer;
  begin
    with bb do
      begin
        myresult := sqnil;
        bbwindex := 0;
        while (myresult = sqnil) and (bbwindex < bbwlen) do
          begin
            wordfirstbit := bitfirstvec[wvec[bbwindex]];
            if wordfirstbit >= 0 then
              myresult := sqxtype(wordfirstbit + (bbwindex * bbwbitlen))
            else
              Inc(bbwindex)
          end
      end;
    BbFirstSq := myresult
  end; { BbFirstSq }

Spooky

CookieCat's search dubbed Spooky is implemented as iterative search using a finite-state machine as nested procedure inside SpookyFindMove, which structure is outlined in following snippet:

  { ***** Spooky search routines ***** }
  procedure SpookyFindMove(var ssc: ssctype);
    procedure SpookyPrepareRoot;
    procedure SpookyIterationSequence;
      procedure SpookyIterate;
        procedure SpookySearch;
          procedure SpookyLimitTestNode;
          procedure SpookyMovePick;
            procedure SpookyOrderMoves;
            procedure SpookyPickThis(index: Integer);
          procedure SpookyMinimax;
        begin  { SpookySearch }
          with ssc do
            while pirvec[ply].nss <> nssexit do
              case pirvec[ply].nss of
                nssplystart:    { Search state: Initialize processing at this node }
                nssfirdrawtest: { Search state: Draw tests for fiftymoves/insufficient/repetition }
                nsstbprobe:     { Search state: Probe the tablebases }
                nssstandtest:   { Search state: Gainer (QSearch ed.) search stand-pat evaluation and test }
                nssgenerate:    { Search state: Move generation }
                nssmovepick:    { Search state: Move pick }
                nssexecute:     { Search state: Execute the move and advance one ply }
                nssretract:     { Search state: Retreat one ply and retract the move }
                nsspostscan:    { Search state: Post move scan operations }
                nssplyfinish:   { Search state: Final processing for this node }
        end;  { SpookySearch }
      end; { SpookyIterate }
    end; { SpookyIterationSequence }
  end; { SpookyFindMove }

Smokey

Smokey is CookieCat's iterative mate finder with nested procedures outlined below:

  { ***** Smokey mate finder routines ***** }
  procedure SmokeyFindMate(var ssc: ssctype; fmvc: Integer);
    procedure SmokeySearch;
      procedure SmokeyApplyKillerBonus;
    begin
      with ssc do
        while pirvec[ply].nss <> nssexit do
          case pirvec[ply].nss of
            nssplystart:
            nsstermtest:
            nssgenerate:
            nssmovepick:
            nssexecute:
            nssretract:
            nsspostscan:
    end; { SmokeySearch }
 end; { SmokeyFindMate }

Lucky

Lucky, CookieCat's evaluation function with evaluation hash table and pawn hash table considers material, pawn structure with focus on passed pawns ^[12], and piece mobility.

Download

^[13]

CookieCat.tar
- Details
- Download
- 468 KB

Forum Posts

2011

Announcement: The Bozochess Project by Steven Edwards, CCC, October 05, 2011
Release date target by Steven Edwards, CCC, October 16, 2011
BozoChess Monday release schedule by Steven Edwards, CCC, December 12, 2011
The name change by Steven Edwards, CCC, December 16, 2011
Number sequence puzzle by Steven Edwards, CCC, December 16, 2011 » Endgame Tablebases ^[14]
CookieCat Monday release schedule by Steven Edwards, CCC, December 19, 2011
Tablebase class name list available by Steven Edwards, CCC, December 19, 2011 » Endgame Tablebases
CookieCat sample games by Steven Edwards, CCC, December 24, 2011
CookieCat goes mulithreaded by Steven Edwards, CCC, December 31, 2011 » Perft

2012 ...

CookieCat's opening book implementation by Steven Edwards, CCC, January 05, 2012 » Opening Book
CookieCat's pawn structure code by Steven Edwards, CCC, January 07, 2012
CookieCat's early search termination by Steven Edwards, CCC, January 07, 2012
CookieCat and Cookie Cat by Steven Edwards, CCC, January 08, 2012
CookieCat source via the net by Steven Edwards, CCC, January 26, 2012
CookieCat and perft by Steven Edwards, CCC, October 14, 2012
For a limited time, two sources by Steven Edwards, CCC, January 22, 2013 » Myopic

External Links

References

^ Free Pascal wiki
^ Release date target by Steven Edwards, CCC, October 16, 2011
^ Announcement: The Bozochess Project by Steven Edwards, CCC, October 05, 2011
^ The name change by Steven Edwards, CCC, December 16, 2011
^ CookieCat source via the net by Steven Edwards, CCC, January 26, 2012
^ Cookie Cat (character) | Steven Universe Wiki
^ Cookie Cat | Steven Universe Wiki
^ Image from The first Spooky and the fifth Smokey (April 7, 1935) from The Birth of Smokey Stover - First Puffs (1935), Bill Holman Comics, Copyright, 1935, by Chicago Tribune, New York News Syndicate Inc., supplied by Carl Linich, posted by Paul Tumey, April 24, 2012
^ Description is based on the source code - CookieCat.pas
^ CookieCat and Cookie Cat by Steven Edwards, CCC, January 08, 2012
^ CookieCat's opening book implementation by Steven Edwards, CCC, January 05, 2012
^ CookieCat's pawn structure code by Steven Edwards, CCC, January 07, 2012
^ Source code courtesy Steven Edwards
^ A018214 - OEIS | Alkane (or paraffin) numbers

What links here?

Page	Date Edited
BitScan	Sep 10, 2017
Bobcat	Jun 27, 2017
Chess 0.5	Nov 20, 2016
CookieCat	Nov 15, 2016
Endgame Tablebases	Mar 6, 2018
Engines	Mar 10, 2018
Murka	Nov 11, 2016
Myopic	Nov 11, 2016
Opening Book	Feb 26, 2018
Pascal	Nov 28, 2016
Spector	Nov 11, 2016
Steven Edwards	Aug 26, 2017
Symbolic	May 8, 2017
WildCat	Nov 11, 2016

Up one level

Critter

GerdIsenberg — Sat, 25 Jan 2014 13:11:36 GMT

Home * Engines * Critter

		Critter, an UCI compatible cross-platform chess engine by Richard Vida, executables freely available for personal use to run under Windows, Linux, Android and Mac OS ^[1] . Starting in late 2008, Critter was first written in Object Pascal compiled with Delphi, now available as open source engine ^[2] ^[3] , and was ported to C / C++ in 2009 ^[4] . It consistently evolved through various board representations from 0x88 to bitboards, as acknowledged by Richard Vida, also incorporating ideas from strong open source programs like Ippolit ^[5] , to a world class engine which achieved top five of most engine rating lists ^[6] .In 2012, Critter had its over the board debut at the ICT 2012, where it became strong runner-up behind the Rybka cluster.
Critter Country ^[7]

Description

Critter applies a principal variation search with aspiration windows, null move pruning ^[8] and other state of the art forward pruning, reduction and extension techniques, such as the Botvinnik-Markoff extensions ^[9] . It can search in parallel with up to eight threads ^[10] , supports Gaviota tablebases ^[11] , and is able to play Chess960 ^[12] . Critter features a tapered eval with a score pair class and overloaded operators ^[13] ^[14] , and blockage detection in late endgames ^[15] .

Selected Games

ICT 2012, round 7, Rybka - Critter ^[16] ^[17]

[Event "ICT12"]
[Site "Leiden"]
[Date "2012.05.13"]
[Round "7"]
[White "Rybka"]
[Black "Critter"]
[Result "1/2-1/2"]
 
1.d4 d5 2.c4 e6 3.Nf3 c6 4.e3 Bd6 5.b3 f5 6.Bd3 Nf6 7.O-O Qe7 8.Bb2 O-O
9.Qc1 b6 10.Ba3 Bb7 11.Bxd6 Qxd6 12.Nc3 dxc4 13.Bxc4 Nbd7 14.Re1 b5
15.Bd3 b4 16.Na4 c5 17.Nxc5 Bxf3 18.gxf3 Rfc8 19.Bc4 Nxc5 20.dxc5 Rxc5
21.a3 bxa3 22.Qxa3 Nd5 23.Red1 Qc7 24.Kg2 Rd8 25.Bxd5 Rdxd5 26.Qa4 Qe7
27.Rxd5 Rxd5 28.Qxa7 Qxa7 29.Rxa7 Rb5 30.Re7 Rb6 31.Kg3 Kf8 32.Rd7 Rxb3
33.Kf4 Rb5 34.h4 h6 35.Kg3 Rb8 36.h5 Re8 37.Rb7 Re7 38.Rb5 Kf7 39.e4 Kf6
40.exf5 exf5 41.Kf4 Re2 42.Rxf5+ Ke6 43.Rb5 Rxf2 44.Rb6+ Kf7 45.Rb7+ Kf6
1/2-1/2

Release Dates

Critter 0.38 : 2009-05
Critter 0.39a : 2009-06
Critter 0.42 : 2009-10
Critter 0.52 : 2010-01
Critter 0.52b : 2010-02
Critter 0.60 : 2010-04
Critter 0.70 : 2010-05
Critter 0.80 : 2010-07
Critter 0.90 : 2010-11
Critter 1.0 : 2011-03
Critter 1.01 : 2011-03
Critter 1.2 : 2011-06
Critter 1.4 : 2011-12
Critter 1.4a : 2012-01
Critter 1.6 : 2012-06
Critter 1.6a : 2012-06

Publications

Arno Nickel (2012). Die schöne neue Welt der Schachengines. SCHACH 2,3,5,6 2012, pdf (German) ^[18]

Forum Posts

2009

Critter 0.34 : 2146 by Patrick Buchmann, CCC, April 18, 2009
Critter 0.38 : 2330 by Patrick Buchmann, CCC, May 22, 2009
Critter 0.40 released by Richard Vida, CCC, July 26, 2009
Critter 0.40 : 2471 by Patrick Buchmann, CCC, August 01, 2009
Critter: Pascal vs C by Richard Vida, CCC, August 27, 2009 » C, Pascal
Critter 0.42 available by Richard Vida, CCC, October 08, 2009 » Pascal
Critter 0.42 : 2649 by Patrick Buchmann, CCC, October 11, 2009

2010

Critter 0.52 available by Richard Vida, CCC, Jan 25, 2010 » C
Critter 0.52b added to the IPON list ... by Ingo Bauer, CCC, February 04, 2010
Strange knight underpromotion by Critter by Richard Vida, CCC, March 04, 2010
Critter goes SMP (version 0.60 is released) by Richard Vida,CCC, April 13, 2010
Critter 0.60: 2718 by Patrick Buchmann, CCC, April 14, 2010
Critter 0.70 is out by Richard Vida, CCC, May 23, 2010
Critter 0.80 by Richard Vida, CCC, July 24, 2010
Critter 0.90 released by Richard Vida, CCC, November 29, 2010
Critter - looking at static evaluation by Richard Vida, CCC, December 11, 2010

2011

Critter 1.0 available by Richard Vida, CCC, March 16, 2011
Critter 1.0 for Linux by Richard Vida, CCC, March 22, 2011 » Linux
My experience with Linux/GCC by Richard Vida, CCC, March 23, 2011
Critter bugfix update by Richard Vida, CCC, March 28, 2011 ^[19]
Critter 1.2 update + new homepage by Richard Vida, CCC, June 25, 2011 » Android
Critter 1.2 SEEMS to be a member of the Ippo family by Kai Laskos, CCC, July 02, 2011
for Pascal fans: Critter by Richard Vida, CCC, September 16, 2011

2012 ...

Re: World Computer Chess Championship ? by Richard Vida, CCC, June 11, 2012
Re: Critter 1.6 released! by Richard Vida, CCC, June 15, 2012
Continuation of Critter would be very appreciated by Mike Scheidl, CCC, May 15, 2013

External Links

Chess Engine

Critter for win32/64, linux and android platforms hosted by Emil Vlasák
SourceForge.net: Critter Chess - Project Web Hosting - Open Source Software (Pascal Version)
Critter (chess) from Wikipedia
Critter at CCRL 40/40

Misc

References

^ Critter for win32/64, linux and android platforms hosted by Emil Vlasák, Mac OS version compiled by Jeremy Bernstein
^ for Pascal fans: Critter by Richard Vida, CCC, September 16, 2011
^ SourceForge.net: Critter Chess - Project Web Hosting - Open Source Software
^ Critter: Pascal vs C by Richard Vida, CCC, August 27, 2009
^ Re: World Computer Chess Championship ? by Richard Vida, CCC, June 11, 2012
^ Critter (chess) from Wikipedia
^ Critter Country from Wikipedia run by The Walt Disney Company
^ Interview with Richard Vida by Frank Quisinsky, February 20, 2010
^ Re: World Computer Chess Championship ? by Richard Vida, CCC, June 11, 2012
^ Critter goes SMP (version 0.60 is released) by Richard Vida, CCC, April 13, 2010
^ Critter 0.70 is out by Richard Vida, CCC, May 23, 2010
^ Critter 0.80 by Richard Vida, CCC, July 24, 2010
^ Re: talk about IPP's evaluation by Richard Vida, CCC, November 07, 2009 » Ippolit, SIMD and SWAR Techniques
^ My experience with Linux/GCC by Richard Vida, CCC, March 23, 2011
^ Chiron 1.1 bug? by Richard Vida, CCC, December 24, 2011
^ Leiden Round 7: Rybka vs Critter by Ray, Rybka Forum, May 13, 2012
^ ICT 12 - PGN download, CSVN
^ Part 1 covers Houdini, Rybka, Komodo, Stockfish, Critter, Naum, Chiron and Spike
^ Difficult position to Critter by Jouni Uski, CCC, March 24, 2011

What links here?

Page	Date Edited
Arno Nickel	Sep 25, 2015
Blockage Detection	Oct 19, 2017
Chiron	Sep 24, 2017
Critter	Jan 25, 2014
Delphi	Dec 16, 2016
Engines	Mar 10, 2018
Gaviota Tablebases	Apr 22, 2018
Houdini	Apr 14, 2018
ICT 2012	Jun 11, 2012
Kai Laskos	Jan 21, 2018
Komodo	Mar 6, 2018
Languages	Nov 26, 2017
Naum	Nov 23, 2017
Richard Vida	Aug 11, 2013
Rybka	Mar 27, 2017
Scid on the Go	Jan 26, 2015
Spike	Jan 7, 2016
Stockfish	Apr 7, 2018
Strelka	May 17, 2016
TCEC Season 5	Jun 2, 2014
TCEC Season 6	Dec 2, 2014
TCEC Season 7	Jan 23, 2015
TCEC Season 9	Nov 6, 2017
Who's Who	Sep 6, 2017

Up one level

Dappet

GerdIsenberg — Mon, 12 Dec 2016 22:00:59 GMT

Home * Engines * Dappet

Dappet,
the chess program by Dap Hartmann and Peter Kouwenhoven, competing all 18 consecutive Dutch Open Computer Chess Championships from 1981 until 1998. It further participated at the WMCCC 1988 in Almeria, the WCCC 1989 in Edmonton, the 3rd Computer Olympiad 1991, and various Aegon Tournaments. Dappet of the late 80s and 90s was written in Turbo Pascal and Assembler to run on an x86 based IBM PC or compatible. It used a 10x12 board ^[1]. It did not utilize the Butterfly Heuristic, proposed by Hartmann in conjunction with Butterfly Boards as a pure thought experiment ^[2].

Description

from the WCCC 1989 booklet ^[3]:

Dappet uses the NegaScout algorithm enhanced with refutation tables, killer heuristic, history heuristic and transposition tables (700,000 entries) to search the game tree. The strategy used is basically brute force, with selective deepening of forced lines of play. The opening book consists of some 15,000 positions.

Sylkar

At two occasions, the DOCCC 1986 and DOCCC 1994, to even the number of entries, a female version of Dappet was entered, Sylkar for Sylvia and Karin ^[4].

Selected Games

DOCCC 1997, round 5, Dappet - Zzzzzz ^[5]

[Event "DOCCC 1997"]
[Site "Alphen a/d Rijn NED"]
[Date "1997.11.23"]
[Round "05"]
[White "Dappet"]
[Black "Zzzzzz 4.2"]
[Result "1-0"]
 
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Bd2 Bxd2+
8.Nbxd2 Nxe4 9.d5 Nxd2 10.Qxd2 Ne7 11.d6 cxd6 12.O-O-O Qc7 13.Qf4 O-O
14.Kb1 Ng6 15.Qe4 Ne5 16.Bd5 g6 17.Rhg1 a6 18.Rge1 Nc6 19.Ng5 Kg7 20.Qh4
h5 21.Nxf7 Rxf7 22.Bxf7 b6 23.Bd5 Bb7 24.Bxc6 1-0

External Links

References

^ Dap Hartmann (2009). A Thesis is more than three unrelated Ideas. Review, ICGA Journal, Vol. 32, No. 2
^ Dap Hartmann (1988). Butterfly Boards. ICCA Journal, Vol. 11, Nos. 2/3, pp. 64-71.
^ Kings Move - Welcome to the 1989 AGT World Computer Chess Championship. Edmonton, Alberta, Canada, Courtesy of Peter Jennings, from The Computer History Museum, pdf
^ Jaap van Oosterwijk Bruyn (1986). Nona retains her Title. ICCA Journal, Vol. 9, No. 3, pp. 160
^ Downloads | Open Dutch Computer Chess Championships | Games

What links here?

Page	Date Edited
More Links
3rd Computer Olympiad	Jul 25, 2017
Aegon 1989	Jan 22, 2017
Aegon 1990	Mar 26, 2017
Aegon 1992	Jan 22, 2017
Aegon 1993	Mar 26, 2017
Aegon 1994	Mar 26, 2017
Aegon 1995	Apr 6, 2017
Aegon 1997	Apr 7, 2017
Arachne	May 22, 2016
Dap Hartmann	Jun 10, 2017
Dappet	Dec 12, 2016
Delft University of Technology	Feb 4, 2018
DOCCC 1981	Nov 14, 2015
DOCCC 1982	Nov 14, 2015
DOCCC 1983	Nov 13, 2015
DOCCC 1984	May 22, 2016
DOCCC 1985	Dec 9, 2016
DOCCC 1986	Dec 9, 2016
DOCCC 1987	Dec 9, 2016
DOCCC 1988	Aug 15, 2015
DOCCC 1989	Aug 15, 2015
DOCCC 1990	Aug 15, 2015
DOCCC 1991	Aug 15, 2015
DOCCC 1992	Dec 12, 2016
DOCCC 1993	Dec 12, 2016
DOCCC 1994	Aug 15, 2015
DOCCC 1995	Jun 7, 2016
DOCCC 1996	Jun 7, 2016
DOCCC 1997	Aug 15, 2015
DOCCC 1998	Feb 25, 2018
Engines	Mar 10, 2018
LChess	Jan 7, 2016
Leiden University	Jul 5, 2016
Mathematician	Apr 9, 2018
October	May 6, 2012
Pachera	Nov 12, 2015
Paul Ramsteijn	Nov 13, 2015
Peter Kouwenhoven	Jan 7, 2016
VAX	Sep 9, 2015
WCCC 1989	Dec 5, 2017

Up one Level

Delfi

GerdIsenberg — Thu, 07 Jan 2016 18:39:08 GMT

Home * Engines * Delfi

		Delfi, a strong WinBoard and UCI compliant chess engine written by Fabio Cavicchio in Pascal with x86 inline assembly, compiled with Delphi, first released in August 2001 ^[1]. Delfi is distributed commercially within a software suite as Delfi Trainer, along with an own "2.5D" chess GUI, a ergonomic 2D graphics board in Bird's-eye view and pieces with 3D-effect, and a position trainer ^[2] . The pure Winboard/UCI engine with some restrictions is further available for free. Formerly an open source engine, Fabio closed the sources past the still available version 2.51, which has a license allowing modification for personal use ^[3].
Delfi's 2.5D Board ^[4]

Description

Delfi uses the vector attacks approach of a board representation with a 16x16 board, combining the property of the 10x12 board with its surrounding ranks and files with the property that a square difference uniquely maps a vector in the Chebyshev vector space of a chessboard. Delfi applies PVS alpha-beta with null move-, futility- and history pruning. Dual core processors are supported using a parallel search with a shared hash table.

Tournament Play

Delfi won all the six Campionato Italiano per Programmi Scacchistici (CIPS) championships it played, from 2002 until 2007, and further won the Chess Computer Cup 2005, and 2008. At the WCCC 2006 in Turin, Delfi performed with respectable 5½/11.

Photos & Games

CIPS 2002

CIPS 2002 round 2: Marco Pagnoncelli and Fabio Cavicchio, CyberPagno vs Delfi ^[5] ^[6]

[Event "CIPS 2002"]
[Site "Pontedera"]
[Date "2002.06.01"]
[Round "2"]
[White "CyberPagno 1.0beta 1.6"]
[Black "Delfi 3.1"]
[Result "0-1"]
 
1.e4 e6 2.d4 d5 3.exd5 exd5 4.Nf3 Bg4 5.h3 Bh5 6.Qe2+ Ne7 7.Nc3 Nc6 8.g4 Bg6
9.Bf4 h5 10.gxh5 Bxh5 11.Nb5 Rc8 12.O-O-O g6 13.Bg2 Bg7 14.c3 a6 15.Na3 O-O
16.Kb1 Nf5 17.Qd2 b5 18.Bg5 Qd7 19.Nc2 Rb8 20.Qd3 b4 21.b3 bxc3 22.Qxc3 Ncxd4
23.Ncxd4 Bxf3 24.Bxf3 Nxd4 25.Bh6 Qf5+ 26.Rd3 Bxh6 27.Qxd4 Bg7 28.Bg4 Bxd4
29.Bxf5 c5 30.Bg4 Rbd8 31.f4 Rfe8 32.Bf3 Re6 33.Rf1 Rf6 34.Bg2 Rf5 35.Kc2 a5
36.Rdd1 Kh7 37.Rde1 a4 38.Kd3 Rb8 39.Rb1 axb3 40.axb3 Bg7 41.Kd2 Bh6 42.Kc2 Ra8
43.b4 c4 44.Ra1 Rxa1 45.Rxa1 d4 46.Rf1 Kg8 47.Be4 Rb5 48.Rd1 Bg7 49.Rb1 Rh5
50.Bg2 Rf5 51.Rf1 Bf6 52.Be4 Rb5 53.Rb1 Kf8 54.Bc6 Rh5 55.Bg2 Rf5 56.Rf1 Ke7
57.Be4 Rb5 58.Rb1 Bg7 59.Bg2 Rf5 60.Rf1 Kd6 61.Be4 Rb5 62.Rb1 Rh5 63.Bg2 Rf5
64.Rf1 Bh6 65.Rf3 Bxf4 66.Rf1 Rf6 67.Rf3 c3 68.Rf2 Ke5 69.b5 Rb6 70.Bc6 f5
71.Rg2 g5 72.Kd3 Bd2 73.Re2+ Be3 74.Rg2 Rb8 75.Ra2 Kd6 76.Ra6 Rf8 77.Ra7 Rh8
78.Bg2 Rb8 79.Ra6+ Kc5 80.Rf6 Kxb5 81.Rxf5+ Kb4 82.Bc6 Rb6 83.Be8 Rb7 84.Bc6
Rb8 85.Rf7 Kc5 86.Bb7 Rh8 87.Bg2 Rb8 88.Bb7 Kd6 89.Rf6+ Ke5 90.Rf7 Rh8 91.Rf3
Bf4 92.Ba6 g4 93.Rf2 gxh3 94.Re2+ Be3 95.Rh2 Bg1 96.Rh1 h2 97.Bc4 Rb8 98.Kc2
Rb2+ 99.Kd1 Rd2+ 100.Kc1 Be3 101.Bd3 Rg2+ 102.Kd1 Rg1+ 103.Kc2 Rxh1 104.Kb3 Re1
105.Kc4 h1=Q 106.Kc5 Qd5+ 107.Kb6 c2 108.Bxc2 d3+ 109.Kc7 dxc2 110.Kc8 Qc6+
111.Kb8 Rb1# 0-1

WCCC 2006

^[7]

Ikarus

WCCC 2006, round 4, Delfi - Ikarus ^[8], Munjong Kolss (back), Fabio Cavicchio and Alex Brunetti

[Event "WCCC 2006"]
[Site "Turin, Italy"]
[Date "2006.05.27"]
[Round "4"]
[White "Delfi"]
[Black "Ikarus"]
[Result "1/2-1/2"]
 
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.d3 Bc5 6.O-O d6 7.Bg5 b5 8.Bb3 h6
9.Bxf6 Qxf6 10.Nc3 O-O 11.a4 Bg4 12.Nd5 Qd8 13.c3 Na5 14.Bc2 c6 15.Ne3 Bxe3 
16.fxe3 Qb6 17.Qd2 c5 18.Bd1 Bxf3 19.Rxf3 b4 20.c4 Qd8 21.Qf2 Ra7 22.Rg3 Kh8 
23.Bh5 Qe8 24.Rf3 Qd7 25.Qc2 Nc6 26.Raf1 f6 27.Qd1 Rb7 28.b3 Rc7 29.Rg3 Qe6 
30.Bg6 Ne7 31.Qh5 Qg8 32.Rff3 Nxg6 33.Rxg6 Rff7 34.Rg4 Rcd7 35.Qf5 Rde7 36.Rh3
Qf8 37.Rgh4 Rc7 38.Rh5 Rce7 39.Kh1 Qg8 40.R5h4 Qf8 41.Rg3 Qe8 42.Rh5 Rb7 43.Kg1
Rfe7 44.Rgh3 Rbc7 45.R5h4 Rb7 46.Kh1 Ra7 47.Rh5 Rad7 48.R3h4 Rb7 49.Kg1 Kg8 
50.Rh3 Rbd7 51.Rg3 Kh8 52.Rh4 Qf7 53.Kh1 Qe8 54.Rf3 Rf7 55.Kg1 Rfe7 56.Kf1 Qf7 
57.Rfh3 Qe8 58.Rh5 Rc7 59.Kg1 Rcd7 60.Kh1 Rb7 61.Rf3 Qf7 62.Rh4 Rbd7 63.Rfh3 
Qe8 64.Rg3 Qf8 65.Rh5 Qf7 66.Rhh3 Qe8 67.Kg1 Qf7 68.Rf3 Re8 69.Rh4 Ree7 70.Rfh3
Qe8 71.Rh5 Rc7 72.Rf3 Rc8 73.Kh1 Rd8 74.Rfh3 Rdd7 75.R3h4 Rb7 76.Kg1 Kg8 77.Rh3 
Rbd7 78.Rg3 Kh8 79.Rh4 Qf7 80.Rf3 Qe8 81.Rg4 Re6 82.Rh3 Ree7 83.Kh1 1/2-1/2

IsiChess

WCCC 2006, round 6, IsiChess - Delfi ^[9], Gerd Isenberg and Alex Brunetti operating Delfi

[Event "WCCC 2006"]
[Site "Turin, Italy"]
[Date "2006.05.29"]
[Round "6"]
[White "IsiChess"]
[Black "Delfi"]
[Result "0-1"]
 
1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 Be7 5.Bg5 h6 6.Bh4 O-O 7.e3 b6 8.cxd5 exd5 
9.Bd3 Bb7 10.O-O Nbd7 11.Rc1 Ne4 12.Bxe7 Qxe7 13.Nxe4 dxe4 14.Rxc7 Bc8 15.Bb5
Qd8 16.Rxc8 Rxc8 17.Nd2 Nf6 18.Qa4 Rc7 19.Nc4 Qd5 20.Ne5 Rfc8 21.Ba6 Re8 22.Be2 
Rb8 23.f3 b5 24.Qa3 Rb6 25.Re1 exf3 26.Bxf3 Qd6 27.Qd3 Qb4 28.Re2 Rd6 29.Qf5 a6 
30.Qb1 Nd7 31.Nd3 Qc4 32.b3 Qc3 33.b4 Rc4 34.g3 Nf6 35.Kg2 Nd5 36.Bxd5 Rxd5 
37.Qd1 Rd6 38.h3 Rc7 39.Kh2 Re6 40.Kg1 Rce7 41.Kf2 Qc6 42.Qe1 Rd6 43.Nc5 Qd5 
44.Nb3 Rf6+ 45.Kg1 Qf3 46.Nd2 Qf5 47.Kg2 Qd5+ 48.Kg1 Rc6 49.Nb3 Qf3 50.Nd2
Qh5 51.Kg2 Rc2 52.e4 Rxa2 53.Qf2 Ra4 54.d5 Rxb4 55.d6 Re8 56.Nf3 Rc4 57.e5 Qf5 
58.Rd2 Rc3 59.Qe2 Qd7 60.Kh2 a5 61.Ne1 b4 62.Nd3 b3 63.Nf4 a4 64.Nd5 Rc1 65.Qe3
Qb5 66.Ne7+ Kh8 67.d7 Rd8 68.e6 b2 69.Ng6+ Kh7 70.exf7 Rh1+ 71.Kxh1 b1=Q+ 72.Kh2
Qxg6 73.Qe8 Qf6 74.Qg8+ Rxg8 75.fxg8=Q+ Kxg8 76.d8=Q+ Qxd8 77.Rxd8+ Kf7 0-1

Forum Posts

2001 ...

Stalemate trap(SOS-Delfi) by George Lyapko, Winboard Forum, December 18, 2001 » Stalemate, Test-Positions, SOS
Delfi won the Italian-ch !! by Frank Quisinsky, CCC, June 02, 2002 » CIPS 2002
Delfi won C.I.P.S 2003, Updates in tournament calendar! by Frank Quisinsky, CCC, June 26, 2002 » CIPS 2003
I Recomend Delfi for any player in the 1800-2000 uscf range! by George Jones, CCC, September 11, 2003

2005 ...

Delfi as UCI by Gabor Szots, CCC, March 02, 2006
CCRL 40/4: Delfi 5.1 is 50 points above Delfi 5.0 by Kirill Kryukov, CCC, April 12, 2007
Delfi 5.2 : 2552 by Patrick Buchmann, CCC, October 01, 2007
Delfi, Multiprocessor support by Tony Thomas, CCC, June 24, 2008
Delfi 5.3B released - memory bug fixed by terminator, CCC, June 25, 2008
Delfi 5.3 : 2544 by Patrick Buchmann, CCC, June 25, 2008
Delfi 5.3b : 2553 by Patrick Buchmann, CCC, July 03, 2008
Delfi 5.4, Counter 0.9, Lime 66, Sissa 0.04 in the UEL by Patrick Buchmann, CCC, August 01, 2008
Pocket Delfi Trainer by Ted Summers, CCC, August 13, 2008

External Links

Chess Engine

Misc

References

What links here?

Page	Date Edited
Alex Brunetti	Jun 1, 2014
Bestia	Jan 5, 2013
CCC 2005	Feb 27, 2014
CCC 2008	Jan 6, 2014
CIPS 2002	Feb 9, 2013
CIPS 2003	Jan 6, 2014
CIPS 2004	Jan 6, 2014
CIPS 2005	Feb 4, 2013
CIPS 2006	Jan 6, 2014
CIPS 2007	Jan 6, 2014
CyberPagno	Oct 5, 2016
Delfi	Jan 7, 2016
Eigenmann Endgame Test	Jun 1, 2017
Engines	Mar 10, 2018
Fabio Cavicchio	Jan 7, 2016
George Lyapko	Jan 14, 2013
Hamsters	Apr 11, 2014
IGWT 2013	Jun 23, 2014
IGWT 2014	Feb 2, 2016
IGWT III	May 15, 2017
IGWT IV	May 17, 2017
Italian Computer Chess Championship	Sep 24, 2017
Kiwi	Sep 2, 2016
Leila	May 8, 2017
Point Value by Regression Analysis	Aug 26, 2017
Pro Deo	Apr 5, 2017
Smash	May 11, 2016
SOS	Apr 5, 2017
Spike	Jan 7, 2016
Stalemate	Feb 21, 2018
Test-Positions	Feb 25, 2018
Timo Haupt	Jan 8, 2016
WCCC 2006	Jan 28, 2018

Up one Level

Delphil

GerdIsenberg — Sat, 17 Sep 2016 17:06:47 GMT

Home * Engines * Delphil

Delphil,
a WinBoard and UCI compliant chess engine written by Philippe Fabiani in Pascal using Delphi 7 ^[1] , first released in April 2004. Delphil started its life as Delphi port of Tom Kerrigan's TSCP, and in 2009, Delphil still owned about 80% of TSCP's code base with move generation and search almost identical. Most changes were done in evaluation, further a tranposition table, various extensions and null move pruning were added ^[2] . Delphil 3.2, released on September 28, 2014, applies a parallel search with up to 32 processors simultaneously, and is able to probe Nalimov Tablebases ^[3] .

Forum Posts

2005 ...

Gauntlet Delphil 1.3 - games by Karl-Heinz Söntges, CCC, April 16, 2005
Gauntlets Liste B 5' + 5" Delphil 1.5a - table, games by Karl-Heinz Söntges, CCC, August 03, 2005
Delphil 1.7 : 2377 by Patrick Buchmann, CCC, June 11, 2007
Delphil 1.8 : 2405 by Patrick Buchmann, CCC, July 01, 2007
Delphil 1.9 : 2300 by Patrick Buchmann, CCC, June 09, 2008
Delphil 1.9b : 2370 by Patrick Buchmann, CCC, July 05, 2008
Delphil 1.9c : 2368 by Patrick Buchmann, CCC, August 10, 2008
Delphil 1.9e : 2313 by Patrick Buchmann, CCC, October 06, 2008
Delphil 1.9f : 2307 by Patrick Buchmann, CCC, November 01, 2008
Delphil 1.9g : 2346 by Patrick Buchmann, CCC, April 06, 2009
Delphil 2.3 : 2368 by Patrick Buchmann, CCC, September 04, 2009

2010 ...

Nice Delphil 2.6a finish against Amundsen 0.80 by Graham Banks, CCC, October 05, 2010 » Amundsen
Delphil 2.9e released by Gabriel Leperlier, CCC, July 13, 2012

2015 ...

ELO inflation ha ha ha by Henk van den Belt, CCC, September 16, 2016 » Stockfish, Match Statistics, Playing Strength, TCEC Season 9 ^[4]

External Links

References

^ Embarcadero Delphi - Early Borland Years (1995-2004) - Wikipedia
^ Fabiani Philippe from blitzchess.fr by Eric Belot (French)
^ Delphil - home
^ Delphil 3.3b2 (2334) - Stockfish 030916 (3228), TCEC Season 9 - Rapid, Round 11, September 16, 2016

What links here?

Page	Date Edited
Delphil	Sep 17, 2016
Engine releases	Apr 23, 2018
Engines	Mar 10, 2018
Match Statistics	Mar 31, 2018
Philippe Fabiani	Sep 15, 2016
Playing Strength	Mar 31, 2018
Stalemate	Feb 21, 2018
Stockfish	Apr 7, 2018
TCEC Season 5	Jun 2, 2014
TCEC Season 6	Dec 2, 2014
TCEC Season 9	Nov 6, 2017
TSCP	Feb 5, 2016

Up one Level

Delta

GerdIsenberg — Sun, 22 May 2016 08:45:06 GMT

Home * Engines * Delta

		Delta, a chess program by Fré Felkers written in Turbo Pascal ^[1]. Delta played eleven Dutch Open Computer Chess Championships in the period from 1985 ^[2] to 1998, best result in 1991 with 2½ out of 7, as well the WMCCC 1990 in Lyon and the IPCCC 1991.
Nile delta at night ^[3] ^[4]

Games

WMCCC 1990

WMCCC 1990, round 1, Delta - Nightmare ^[5]

[Event "WMCCC 1990"]
[Site "Lyon, France"]
[Date "1990.11.24"]
[Round "1"]
[White "Delta"]
[Black "Nightmare (D)"]
[Result "1-0"]
 
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Nc6 7. O-O Bg4
8. Bf4 Nxd4 9. Bxe4 dxe4 10. Qxd4 exf3 11. Re1+ Be6 12. Qxd8+ Kxd8 13. Rd1+ Kc8
14. gxf3 h5 15. Nc3 a6 16. Nd5 Bxd5 17. Rxd5 g6 18. Re1 Bb4 19. c3 Bd6 20. Bxd6
cxd6 21. Rxd6 g5 22. Re7 f5 23. Re5 Kc7 24. Rg6 Rag8 25. Rxg8 Rxg8 26. Rxf5 Kd6
27. Rf6+ Ke5 28. Rb6 g4 29. Kg2 Rg7 30. h3 gxh3+ 31. Kxh3 Rf7 32. Kh4 Rxf3
33. Rxb7 Rxf2 34. Kxh5 Ke4 35. Kg4 Rd2 36. c4 Kd4 37. Rd7+ Ke3 38. Rxd2 Kxd2
39. c5 1-0

DOCCC 1991

DOCCC 1991, round 5, Zzzzzz 0.1 - Delta ^[6]

[Event "DOCCC 1991"]
[Site "Utrecht NED"]
[Date "1991.10.??"]
[Round "5"]
[White "Zzzzzz 0.1"]
[Black "Delta"]
[Result "0-1"]
[ECO "A10"]
 
1.c4 f5 2.g3 Nf6 3.Bh3 e6 4.Nc3 Bb4 5.Nf3 Nc6 6.d3 Ng4 7.Bg5 Nf6
8.Kf1 h6 9.Bxf6 Qxf6 10.Nb5 Ba5 11.Qb3 d6 12.e3 Bd7 13.Qa3 O-O 14.Nbd4 Nxd4
15.exd4 Bb6 16.d5 a5 17.Qb3 Ba4 18.Qc3 Qxc3 19.bxc3 e5 20.Nh4 Bc2 21.Ke2 e4
22.dxe4 fxe4 23.Be6+ Kh7 24.Bf5+ g6 25.Bxg6+ Kg7 0-1

Namesake

Delta by Dave Wilson

External Links

Chess Program

Delta's ICGA Tournaments

Misc

References

^ Jaap van Oosterwijk Bruyn (1986). Nona retains her Title. ICCA Journal, Vol. 9, No. 3, pp. 160 » DOCCC 1986, Nona
^ Jaap van Oosterwijk Bruyn (1985). The Dutch Computer-Chess Championship 1985 - Nona Prima Donna. ICCA Journal, Vol. 8, No. 4, pp. 248, pp. 252: Delta on its home ground, F. Felkers, its author, in action
^ Nile Delta from Wikipedia
^ Nile River Delta at Night : Image of the Day from NASA Earth Observatory
^ Lyon 1990 - Chess - Round 1 - Game 5 (ICGA Tournaments)
^ Downloads | Open Dutch Computer Chess Championships | Games

What links here?

Page	Date Edited
Delta	May 22, 2016
Delta (GB)	Dec 9, 2012
DOCCC 1985	Dec 9, 2016
DOCCC 1986	Dec 9, 2016
DOCCC 1987	Dec 9, 2016
DOCCC 1988	Aug 15, 2015
DOCCC 1990	Aug 15, 2015
DOCCC 1991	Aug 15, 2015
DOCCC 1993	Dec 12, 2016
DOCCC 1994	Aug 15, 2015
DOCCC 1995	Jun 7, 2016
DOCCC 1996	Jun 7, 2016
DOCCC 1998	Feb 25, 2018
Engines	Mar 10, 2018
Fré Felkers	May 22, 2016
IPCCC 1991	Jun 9, 2016
WMCCC 1990	Oct 27, 2016

Up one level

Diogenes

GerdIsenberg — Fri, 08 Jan 2016 15:46:57 GMT

Home * Engines * Diogenes

		Diogenes, a chess program by Jörg Burwitz. Diogenes is a DOS-program written in Turbo Pascal. It uses a fast, incremental updated evaluation, and applies a principal variation search with none recursive null move pruning of R=2, razoring, and has no Hash tables ^[1]. Diogenes played several International Paderborn Computer Chess Championships, Aegon Tournaments ^[2] and three World Microcomputer Chess Championships, Munich 1993, Paderborn 1995 and Jakarta 1996 ^[3] .
Diogenes sitting in his tub ^[4]

Screenshot

Diogenes ^[5]

Forum Posts

Help With Diogenes by Mark Loftus, CCC, October 02, 1998
Re: Diogenes ! by Jörg Burwitz, CCC, July 18, 1999

External Links

Chess Engine

Diogenes

Diogenes from Wikipedia

References

^ Summer98-Tournament: Description by Torsten Schoop
^ AEGON Tournaments Computer Results Summary
^ Diogenes' ICGA Tournaments
^ Diogenes sitting in his tub. Painting by Jean-Léon Gérôme (1860) from Wikipedia
^ Septober - Computerschach by Herbert Marquardt

What links here?

Page	Date Edited
Aegon 1995	Apr 6, 2017
Aegon 1996	Jan 22, 2017
Confucius	Aug 24, 2013
Diogenes	Jan 8, 2016
Engines	Mar 10, 2018
IPCCC 1993	Nov 1, 2016
IPCCC 1994	Jul 31, 2013
IPCCC 1997	Aug 24, 2013
IPCCC 1998	Feb 25, 2018
IPCCC 1999	Dec 21, 2012
Jörg Burwitz	Jan 8, 2016
Karsten Bauermeister	Sep 6, 2015
Milobarus	Nov 23, 2016
Pschach	Mar 22, 2016
WMCCC 1993	Dec 30, 2017
WMCCC 1995	Jan 3, 2018
WMCCC 1996	Sep 15, 2016

Up one level

Eveann

GerdIsenberg — Mon, 03 Apr 2017 21:47:02 GMT

Home * Engines * EveAnn

EveAnn,
a WinBoard compliant chess engine written by Andres Valverde in Delphi, first released in December 2005 ^[1]. EveAnn started its life when Andres translated Pham Hong Nguyen's FirstChess from C to Pascal, and made it play legal chess. He further improved the program after studying Bruce Moreland's site on chess programming topics, got several ideas from Tom Kerrigan's TSCP and Ed Schröder's How Rebel plays chess. The engine is dedicated to Andres' daughters Eve and Ann ^[2]. EveAnn played the CCT8 in 2006, the CCT9 and under the handle DelTomateX, the WCRCC 2007, the First Annual ACCA World Computer Rapid Chess Championship.

Program Techniques

^[3]

Alpha-Beta search with iterative deepening
Aspiration window in three phases (50, 200, infinite)
Quiescence search with check evasions
Adaptive null move pruning (Fixed to R=3 since 1.66)
SEE for move ordering and QS pruning
Transposition table in a single way (Improved in 1.67)
Lazy Evaluation
History heuristic for move ordering and pruning
Killer heuristic
LMR and LMP
Checks, pawns to 7th and singular extensions
Evaluation includes pawn structure, mobility, a few endgame patterns, king safety, center control, etc.
Rebel Book (Thanks to Ed and Jeroen)
EGGB bitbases supported. Thanks to Daniel Shawul (Scorpio) for his permission.

Selected Games

WCRCC 2007, round 8, EveAnn (DelTomateX) - Horizon ^[4]

[Event "WCRCC 2007"]
[Site "Internet Chess Club"]
[Date "2007.07.21"]
[Round "8"]
[White "EveAnn"]
[Black "Horizon"]
[Result "1-0"]
 
1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e6 5.Nc3 Qc7 6.Be3 a6 7.Bd3 Nf6
8.O-O Ne5 9.h3 Bc5 10.Kh1 d6 11.f4 Ng6 12.Qe1 O-O 13.f5 Ne5 14.Qh4
Bd7 15.Rf3 Nxf3 16.gxf3 Qb6 17.Rg1 Bxd4 18.e5 g6 19.Bxd4 Qc6 20.fxg6
Qxf3+ 21.Kh2 fxg6 22.Bxg6 1-0

Forum Posts

2005 ...

EveAnn engine released by Andres Valverde, CCC, December 18, 2005
EveAnn 1.62 like UCI engine by Silvian Rucsandescu, Winboard Forum, March 18, 2007
EveAnn 1.63 and Dirty 20/07/2007 released by Andres Valverde, CCC, July 31, 2007

2010 ...

Simple question about SEE by Andres Valverde, CCC, January 12, 2011 » Static Exchange Evaluation
EveAnn 1.64 released by Andres Valverde, CCC, February 06, 2011
EveAnn 1.66 released by Andres Valverde, CCC, April 27, 2011
EveAnn 1.67 released by Andres Valverde, CCC, January 23, 2012
EveAnn 1.71 released by Andres Valverde, CCC, February 02, 2013
EveAnn 1.71a by Andres Valverde, CCC, February 05, 2013
EveAnn 1.72 released by Andres Valverde, CCC, December 31, 2013

2015 ...

EveAnn 1.72 released by Andres Valverde, CCC, April 01, 2017

External Links

Andres Valverde Home Site
readme.txt
Norbert's collection/EveAnn (Compilation) by Norbert Raimund Leisner, hosted by Kirill Kryukov
EveAnn from WBEC Ridderkerk

References

^ EveAnn from WBEC Ridderkerk
^ readme.txt
^ from readme.txt
^ 2007 World Computer Rapid Chess Championships | Results | PGN Download

What links here?

Page	Date Edited
Andres Valverde	Apr 6, 2013
CCT8	Apr 6, 2013
CCT9	Aug 25, 2013
Dirty	Nov 14, 2017
Engine releases	Apr 23, 2018
Engines	Mar 10, 2018
Eveann	Apr 3, 2017
Pradu Kannan	Aug 3, 2015
WCRCC 2007	Nov 21, 2016

Up one level

Fafner

GerdIsenberg — Fri, 08 Jan 2016 12:31:03 GMT

Home * Engines * Fafner

		Fafner, a chess program by Guy Burkill, first written in Basic and Assembly to run on Burkill's self built 6502 computer. Fafner played the First PCW Microcomputer Chess Championship 1978 ^[1] , and Fafner 2, written in Pascal and Assembly, supported by Alex Kidson ^[2] , the Third PCW Microcomputer Chess Championship aka the First World Microcomputer Chess Championship 1980 in London.
Fafner the dragon ^[3]

External Links

Chess Program

Fafner's ICGA Tournaments

Misc

References

^ David Levy (1978). The PCW Microcomputer Chess Championships, Personal Computer World, November 1978
^ Kevin O’Connell (1980). World Microcomputer Chess Championship. Personal Computer World, November 1980
^ Fáfnir guards the gold hoard in this illustration by Arthur Rackham to Richard Wagner's Siegfried, Fafnir from Wikipedia

What links here?

Page	Date Edited
Fafner	Jan 8, 2016
Guy Burkill	Jan 8, 2016
Killer Chess	Jan 8, 2016
Max	Dec 23, 2017
Mike	Jan 8, 2016
PCW-MCC 1978	Dec 9, 2012
WMCCC 1980	Dec 25, 2017

Up one Level

Goldbar

GerdIsenberg — Thu, 23 Jul 2015 20:05:38 GMT

Home * Engines * Goldbar

		Goldbar, a private chess program by Bart Goldhoorn whose development started in the early 90s as a Pascal port of an old version of Nightmare by Joost Buijs ^[1]. Initially using an own GUI, it evolved to an UCI compatible program with a parallel search in the 2000s, using the Free Pascal compiler withing the Lazarus (IDE). Goldbar participated ten times the Dutch Open Computer Chess Championship - as Goldbar 92 a strong debut and tied fifth at the DOCCC 1992, four times the Aegon Tournament, five times the International CSVN Tournament, and the CCT14 and Sixth ACCA World Computer Rapid Chess Championship online tournaments in 2012 ^[2]. In May 2014, Goldbar won the CSVN 1st Open Internet Tournament ^[3], in July 2014, the WCRCC 2014 ^[4].
Gold bar 250 kg ^[5]

Photos & Games

ICT 2011, Bart Goldhoorn and Johan de Koning, Goldbar - The King ^[6] ^[7]

[Event "ICT 2011"]
[Site "Leiden"]
[Date "2011.06.12"]
[Round "6"]
[White "Goldbar"]
[Black "The King"]
[Result "1/2-1/2"]
 
1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3
O-O 9. h3 Nb8 10. a4 Bb7 11. axb5 axb5 12. Rxa8 Bxa8 13. Bc2 c5 14. Na3 b4 15.
Nc4 Nc6 16. Ne3 d5 17. exd5 Nxd5 18. Nc4 Bf6 19. Ba4 e4 20. Rxe4 Nce7 21. Re1
Ng6 22. Bc2 Ndf4 23. Bxg6 Nxg6 24. cxb4 cxb4 25. d3 Bb7 26. Re3 Be7 27. b3 Qd7
28. Bb2 f6 29. Qe1 Rb8 30. Nfd2 Bc6 31. d4 Bd5 32. h4 Bf8 33. f3 Nf4 34. g3 Ne6
35. Kh2 Nc7 36. Qf2 Qc6 37. Re1 Ra8 38. Ne3 Be6 39. Rc1 Qb7 40. Nec4 Ra2 41.
Ra1 Rxa1 42. Bxa1 f5 43. Bb2 Nd5 44. Qe2 Qc8 45. Qd3 g6 46. Ne5 Bh6 47. f4 Nf6
48. Ndc4 Qa6 49. d5 Bxd5 50. Ne3 Qxd3 51. Nxd3 Ng4+ 52. Nxg4 fxg4 53. Nxb4 Bxb3
54. Nd3 Be6 55. Kg2 Kf7 56. Kf2 Bf5 57. Ke3 Ke6 58. Kd4 Bg7+ 59. Ke3 Bf8 60.
Kd4 h6 61. Nc5+ Kd6 62. Nd3 Kd7 63. Nc5+ Kc6 64. Nd3 Kb5 65. Bc3 Be7 1/2-1/2

Forum Posts

Goldbar 99 for Download by Đorđe Vidanović, Winboard Forum, January 02, 2000
Diep-GoldBar by Stan Arts, CCC, June 05, 2005
Goldbar games ACCA 2012 by Bart Goldhoorn, CCC, July 16, 2012 » WCRCC 2012

External Links

References

^ Communicated by Joost Buijs, July 13, 2015
^ Goldbar games ACCA 2012 by Bart Goldhoorn, CCC, July 16, 2012
^ Goldbar winnaar 1e CSVN Internettoernooi, CSVN site
^ 2014 Eighth Annual ACCA World Computer Rapid Chess Championships - Results
^ The world's largest gold bar at the Toi gold mine, Gold bar from Wikipedia
^ ICT11 Round 7, CSVN site
^ Downloads | CSVN International Computerchess Tournament | Games, CSVN site

What links here?

Page	Date Edited
1st CSVN OIT	May 18, 2014
ACCA World Computer Rapid Chess Championship	Jun 27, 2017
Aegon 1993	Mar 26, 2017
Aegon 1994	Mar 26, 2017
Aegon 1996	Jan 22, 2017
Aegon 1997	Apr 7, 2017
Bart Goldhoorn	Jan 2, 2017
CCT14	Aug 23, 2012
CCT15	Oct 21, 2014
CCT16	May 13, 2014
CSVN Open Internet Tournament	Aug 31, 2014
DOCCC 1992	Dec 12, 2016
DOCCC 1993	Dec 12, 2016
DOCCC 1995	Jun 7, 2016
DOCCC 1996	Jun 7, 2016
DOCCC 1997	Aug 15, 2015
DOCCC 1999	Aug 15, 2015
DOCCC 2000	Aug 15, 2015
DOCCC 2002	Nov 24, 2017
DOCCC 2004	Nov 19, 2016
DOCCC 2010	Aug 15, 2015
Engines	Mar 10, 2018
Goldbar	Jul 23, 2015
ICT 2001	Oct 14, 2015
ICT 2002	Nov 19, 2016
ICT 2004	Aug 17, 2016
ICT 2005	Oct 14, 2015
ICT 2011	Mar 9, 2012
Joost Buijs	Dec 19, 2016
Neurosis	Dec 23, 2017
Telepath	Jul 14, 2014
WCRCC 2011	Oct 21, 2014
WCRCC 2012	Jul 14, 2014
WCRCC 2013	Jul 14, 2014
WCRCC 2014	Jul 27, 2014
WCRCC 2015	Jul 19, 2015
WCRCC 2016	Jun 27, 2017
WCRCC 2017	Jun 27, 2017

Up one Level

Wikispaces : chessprogramming - items matching description

Ananse

Table of Contents

Description

The Fritz Game

See also

Forum Posts

External Links

References

What links here?

BBchess

Table of Contents

Namesake

External Links

References

What links here?

Bestia

Table of Contents

Photos & Games

See also

Forum Posts

External Links

Chess Engine

Bestia Misc

Beast

References

What links here?

Betsy

Table of Contents

See also

Forum Posts

External Links

Chess Engine

Misc

References

What links here?

BlackBishop

Table of Contents

See also

Forum Posts

External Links

Chess Engine

Misc

References

What links here?

Bobby

Table of Contents

Photos & Games

Mephisto

Sun Phoenix

Strategic Quiescence Search

Pseudo Code

Eval+

History Update

See also

Publications

External Links

References

What links here?

Centaur

Table of Contents

Screenshot

Photos & Games

Descriptions

1989

1991

1993

1999

See also

Publications

Forum Posts

External Links

References

What links here?

Chat

Table of Contents

Selected Games

See also

External Links

References