Wikispaces : chessprogramming - items matching description

Battery

GerdIsenberg — Sun, 29 Jan 2017 09:03:57 GMT

Home * Chess * Tactics * Battery

		A Battery in chess is a formation of two or more sliding pieces with common attacking directions along the same rank, file, or diagonal. Their attacks conjoin on one or more target squares in one ray-direction, attacked at least once directly, and one or more times indirectly. A battery is a chess tactics related term, often motivated by strategic pawn structure related considerations. In the middlegame, a (rook) battery attacking a weak opponent pawn on a half-open file is a common motive. The German chess term Drucksäule ^[1] (tower of strength) refers to own, apparently weak pawn support from its rearspan, to force a lever and pawn exchange to (half-) open a file.
Battery of English cannon ^[2]

Evaluation Considerations

Evaluation Considerations

Like other X-ray related tactics, considering batteries may be subject of king safety terms and static exchange evaluation. A standard pattern in mate at a glance is a battery of bishop / queen or rooks / queen, where the queen attacks a square or opponent piece adjacent to the opponent king, exclusively defended.

Whether a (rook-) battery deserves a general bonus in evaluation is debatable, assuming there are already singular bonuses for occupying open- or half-open files or the seventh rank respectively. Larry Kaufman even proposed a rook-pair penalty with respect to a bishop pair ^[3]:

In my opinion, another reason is that any other pair of pieces suffers from redundancy. Two knights, two rooks, bishop and knight, or major plus minor piece are all capable of guarding the same squares, and therefore there is apt to be some duplication of function.

With two bishops traveling on opposite colored squares there is no possibility of any duplication of function. So, in theory, rather than giving a bonus to two bishops, we should penalize every other combination of pieces, but it is obviously much easier to reward the bishop pair.

External Links

Battery (chess) from Wikipedia
Alekhine's gun from Wikipedia
Battery from Wikipedia
Zbigniew Seifert - Impressions (John Coltrane), from Kilimanjaro, live at Club Pod Jaszczurami, Kraków, November, 14, 1978, YouTube Video
feat. Mieczysław Górka, Janusz Grzywacz, Jarosław Śmietana, Zbigniew Wegehaupt
Anthony Braxton - Impressions (John Coltrane), Woodstock Jazz Festival,1981, YouTube Video
feat. Miroslav Vitouš, Jack DeJohnette, Chick Corea

References

^ Die Drucksäule (German)
^ Artillery battery from Wikipedia
^ Larry Kaufman (1999). The Evaluation of Material Imbalances. (first published in Chess Life March 1999, online version edited by Dan Heisman)

What links here?

Page	Date Edited
Battery	Jan 29, 2017
Dictionary	Aug 24, 2017
Mate at a Glance	Sep 24, 2014
Move Ordering	Feb 27, 2018
Skewer	Oct 22, 2014
Tactics	Jan 12, 2018
X-ray	Apr 12, 2017
X-ray Attacks (Bitboards)	Mar 31, 2015

Up one Level

Blockade

GerdIsenberg — Thu, 19 Oct 2017 11:33:38 GMT

Home * Chess * Blockade

Blockade,
a chess term concerning the mobility of pawns and pieces, most commonly used in the context of blockade of stop or telestop squares of passed pawns by minor pieces as elaborated by Aron Nimzowitsch in The Blockade ^[1] and My System (first restrain, next blockade, lastly destroy) ^[2].

Ambiguity

^[3]

A Block (blockade) is a term for interrupting the attacking ray of a sliding piece, such as blocking a distant check by interposing a pawn or piece
The Blockage (blockade) refers to pawn, piece and king placement, typically in late endgames or pawn endgames which prevents the enemy king or pieces to attack own pawns
The Blockade also refers to a chess tactics where a decoy sacrifice is conducted to decisively reduce the mobility of pieces or king as start of a combination

Publications

Aron Nimzowitsch (1925). Die Blockade. Bernhard Kagan, Berlin, English version by Philip Hereford (1929). The Blockade. German online version edited by Wilfried Krebbers, nimzowitsch.net
Aron Nimzowitsch (1925,1927). Mein System. Bernhard Kagan, Berlin, English version by Philip Hereford (1930). My System. Harcourt, Brace and Company, German online version edited by Wilfried Krebbers, nimzowitsch.net ^[4]
Yuri Averbakh (1985). Chess Tactics for Advanced Players. Pergamon Press, Part 2 The Combinantion, Drawing Combinations, The blockade pp. 245, 2008 edition by Labate Chess, 2012 edition by Ishi Press with introduction by Sam Sloan
Lyudmil Tsvetkov (2010, 2012). Little Chess Evaluation Compendium. December 03, 2012 pdf

External Links

References

^ Aron Nimzowitsch (1925). Die Blockade. Bernhard Kagan, Berlin, English version by Philip Hereford (1929). The Blockade.
^ Nimzowitsch’s My System by Edward Winter
^ Blockade (Glossary of chess) from Wikipedia
^ My System (with The Blockade and other writings) review by Jeremy Silman

What links here?

Page	Date Edited
Bishops of Opposite Colors	Aug 22, 2012
Blockade	Oct 19, 2017
Blockade of Stop	Oct 11, 2016
Chess	Jan 21, 2018
Decoying	Jan 12, 2015
Dictionary	Aug 24, 2017
Fortress	Feb 1, 2018
Mobility	Jan 17, 2018
Pawn Rams (Bitboards)	Nov 11, 2017
Square Control	Sep 15, 2016
Tactics	Jan 12, 2018
Trapped Pieces	Oct 11, 2016

Up one Level

Check

GerdIsenberg — Thu, 01 Feb 2018 19:43:04 GMT

Home * Chess * Check

		Inside a game of chess, a check occurs if a king is under immediate attack by one (or two) opponent pieces. If the king has no way to remove it from attack on the next move, the check is even checkmate. Since check is crucial concerning the outcome of game and the horizon effect, check extensions might be applied to evade the check.
Samuel Bak - Lighthouse ^[1]

Kind of Checks

Single Check

The king is attacked by one opponent piece, either by the piece which just moved directly attacking the king, or alternatively a discovered check where a distant sliding piece attacks the king by opening the ray in opponent king direction with another piece.

Double Check

A double check occurs if the moving piece directly attacks the king but also discovers a distant sliding attacker.

In Check Detection

Whether the side to move is in check is essential to know inside the search for various reasons. It might be checkmate, and most pseudo-legal moves generated may be illegal, leaving the king attacked. Null move would yield in an illegal position as well, at or below the horizon we don't want to stand pat if material balance or static evaluation is far greater than beta.

By last Move

The cheapest and most straightforward way to detect checks is to consider the previous move just made by the opponent. It might be a direct check or discovered check, so one has to test whether piece on target square attacks the king, or whether piece on origin square is attacked by an own sliding piece on an otherwise open ray in opponent king direction ^[2]. If the last move was an en passant capture, one has to consider a few more complicated cases of possible discovered checks, since the captured pawn is not on the target square, and two pawns disappear from the 4th (5th) rank.

Attack Tables

Based on the design and data structure of a chess program, an incremental updated attack and defend map may immedeatly answer whether the king is under attack of one or even two opponent pieces.

On the Fly

With bitboards one may determine a square attacked as mentioned in checks and pinned pieces.

Getting out of check

While in check, it is recommended to perform a specialized Move Generation for check evasion of either a reasonable subset of all pseudo-legal moves or even a strict legal move generation:

Double Check

Only king moves to non attacked squares, sliding check x-rays the king

Single Check

Capture of checking piece. The capturing piece is not absolutely pinned
King moves to non attacked squares, sliding check x-rays the king
Interposing moves in case of distant sliding check. The moving piece is not absolutely pinned.

Perpetual Check

A perpetual check occurs if one player forces an "endless" series of checks with repeated reversible moves, finally resulting in a draw by threefold repetitions.

Publications

Richard L. Smith, Fernand Gobet, Peter Lane (2009). Checking chess checks with chunks: A model of simple check detection. ICCM 2009 » CHREST, Chunking

Forum Posts

1997 ...

quiescence search by Andrew Tridgell, rgcc, April 16, 1997 » Quiescence Search, Crafty

2000 ...

Checks in the Qsearch by Scott Gasch, CCC, June 28, 2002 » Quiescence Search
Idea for check function by Zach Wegner, CCC, November 14, 2002
Fast check detection in bitboard engine by Jean-Francois Romang, CCC, December 10, 2003
Rebel's long checks concept in QS by milix, CCC, January 23, 2004 » Rebel, Quiescence Search
Qsearch Checks by Tor Lattimore, CCC, August 29, 2004 » Quiescence Search
Checks in QSearch by Dan Honeycutt, Winboard Programming Forum, November 23, 2004 » Checks in Quiescence Search

2005 ...

in check test by Anonymous , Winboard Forum, July 07, 2005
How to Best Limit Checks in the Quiescence ? by Stuart Cracraft, CCC, August 20, 2007 » Checks in Quiescence Search
discovered check definition by Uri Blass, CCC, September 12, 2007 » Discovered Check
checks in q-search by Robert Hyatt, CCC, September 02, 2008

2010 ...

Standpat and check by Vlad Stamate, CCC, February 06, 2010 » Standing Pat
Detecting Checks by beneficii, Winboard Programming Forum, November 27, 2010
out of check move ordering by Don Dailey, CCC, March 12, 2011 » Move Ordering
checks in quies by Larry Kaufman, CCC, March 22, 2012 » Quiescence Search
What is (in your opinion) the best check validation method? by goodgame0111, OpenChess Forum, February 24, 2014
Spite checks by Harm Geert Muller, CCC, May 13, 2014

2015 ...

Check-extension in QS by Harm Geert Muller, CCC, April 03, 2015 » Checks in Quiescence Search
Ostrich tactics and pointless checks by Colin Jenkins, CCC, May 29, 2015 » Horizon Effect
Checks in qsearch - must-have or optional? by Martin Fierz, CCC, March 15, 2016 » Checks in Quiescence Search
perpetual check position by Erin Dame, CCC, August 16, 2016
Spite checks, again by Harm Geert Muller, CCC, October 23, 2016

External Links

References

^ Chess in the Art of Samuel Bak, Center for Holocaust & Genocide Studies, University of Minnesota
^ Idea for check function by Zach Wegner, CCC, November 14, 2002

What links here?

Page	Date Edited
AI Chess	Jan 7, 2016
Anastasios Milikas	Nov 29, 2017
Andrew Tridgell	Aug 3, 2015
Anechka	Mar 20, 2014
Atomic Chess	Nov 26, 2016
BCP	Dec 30, 2015
Bebe	Dec 23, 2017
BELCT 2001	Apr 4, 2017
Blockade	Oct 19, 2017
Bobby	Jan 7, 2016
BootChess	May 16, 2017
BP	Jan 7, 2016
Carballo	Oct 2, 2016
Check	Feb 1, 2018
Check Extensions	Apr 19, 2018
Checkmate	Apr 13, 2018
Checks and Pinned Pieces (Bitboards)	Aug 14, 2013
Cheng	Jul 30, 2017
Chess	Jan 21, 2018
Chess Champion Mark V	Sep 7, 2017
Chess Game	Mar 28, 2017
Chess Wizard	Dec 22, 2014
chess22k	Apr 23, 2018
ChessBrainVB	Jun 24, 2017
Crafty	Jan 28, 2018
CXG Sphinx	Jun 23, 2017
Cyrus 68K	Jan 7, 2016
Dabbaba	Oct 21, 2014
Dan Honeycutt	Mar 13, 2014
Diablo	May 17, 2016
Dictionary	Aug 24, 2017
DirGolem	Jun 5, 2016
Discovered Check	Feb 1, 2018
Djinn	Feb 8, 2016
Double Attack	Oct 22, 2014
Double Check	Apr 4, 2013
Dragon FR	Sep 9, 2016
Draw	Apr 14, 2018
DrunkenMaster	Nov 1, 2016
Encoding Moves	Mar 27, 2016
Erin Dame	Dec 2, 2017
Eveann	Apr 3, 2017
FCP	Jun 15, 2013
Fidelity	Jan 7, 2016
Fortress	Feb 1, 2018
Futility Pruning	Aug 30, 2017
Genie	Feb 7, 2016
George Baylor	Sep 22, 2014
Ghost	Feb 2, 2018
Gibbon	Dec 23, 2014
HAL	Jun 14, 2016
Harm Geert Muller	Mar 31, 2018
Horizon Effect	Sep 10, 2017
Interference	May 20, 2011
Kaissa	Apr 9, 2018
King	Feb 26, 2013
Knowledge	Jul 22, 2017
Lachex	Jan 7, 2016
Larry Kaufman	Jan 28, 2018
Laser	Dec 27, 2017
Late Move Reductions	Sep 25, 2017
Legal Move	Feb 16, 2017
Losing Chess	Sep 18, 2017
Martin Fierz	Apr 26, 2018
Mate Search	Oct 22, 2016
Mater	Apr 26, 2016
Maverick	Jan 7, 2016
MessChess	Mar 6, 2014
Monarch	Nov 19, 2014
Move Generation	Jan 29, 2018
Move Ordering	Feb 27, 2018
Moves	Feb 19, 2018
Murka	Nov 11, 2016
One Reply Extensions	Dec 31, 2014
Overloading	May 5, 2017
Pawn Race	Dec 16, 2017
Pertti Saariluoma	Jun 13, 2017
Pin	Mar 7, 2017
Point Value	Mar 31, 2018
ProChess IT	Sep 30, 2015
Pseudo-Legal Move	May 23, 2015
python-chess	Nov 4, 2017
Querg	Dec 11, 2013
Quiescence Search	Aug 19, 2017
Quiet Moves	Mar 4, 2010
Rebel	Feb 25, 2018
Repetitions	Jan 16, 2018
Retrograde Analysis	Mar 21, 2017
RISC 2500	Jan 7, 2016
Scott Gasch	Nov 29, 2016
SCP	Jun 16, 2016
Search Explosion	Mar 30, 2017
SEE	Jan 14, 2013
SEX Algorithm	Nov 25, 2014
Skewer	Oct 22, 2014
Stalemate	Feb 21, 2018
Static Exchange Evaluation	Dec 14, 2017
Stuart Cracraft	May 19, 2017
SuperChess	Dec 7, 2016
Tactical Moves	Sep 22, 2010
Tactics	Jan 12, 2018
Tao	Jan 8, 2016
Test-Positions	Feb 25, 2018
Tor Lattimore	Jan 13, 2013
Turochamp	Dec 14, 2017
Undermining	Jun 10, 2012
Vlad Stamate	Dec 31, 2014
WildCat	Nov 11, 2016
Winter	Jan 23, 2018
Zappa	Oct 24, 2017
Zeus	Jan 3, 2018

Up one Level

Checkmate

GerdIsenberg — Fri, 13 Apr 2018 13:06:42 GMT

Home * Chess * Checkmate

		Checkmate (often shortened to mate) occurs if a king is under immediate attack by one (or two) opponent pieces (in check) and has no way to remove it from attack on the next move. Checkmate is the object of the game of chess, it ends with the mate giving player as the winner, and the mated player the loser.
Shannon Larratt - Fool's mate (2007) ^[1] ^[2] ^[3]

Mate Score

At the Root

At the root the score of a mated player is the worst score one can get, that is a negative score with the greatest absolute value of the score range. It is quite common and sufficient to use something like this in C, C++:

#include <limits.h>
/* (-32768/2 = -16384) */
#define VALUE_MATED (SHRT_MIN/2)

Inside a 16-bit short integer range, assuming centipawn evaluation, it translates to roughly being 16 queens down. Note that using SHRT_MIN instead of SHRT_MIN/2 as mate value has issues in greater/less comparisons of additive expressions, where summands around SHRT_MIN or SHRT_MAX may under- or overflow, which has somehow relaxed with the advent of the usual 32-bit sign-extension.

Down the Tree

Inside a negamax based search, most ^[4] programs assign VALUE_MATED + ply distance to the root as worst case score if entering a node, which if propagated as mate score along the Principal variation to the root, translates in mate in odd plies (positive values), or getting mated in even plies. However, those scores need ply-adjustment if stored as exact score inside the transposition table, and re-adjustment if retrieving from TT. An alternative approach, not only related to mate scores was proposed by Harm Geert Muller, The Delay Penalty as implemented in Micro-Max ^[5] ^[6] ^[7] ^[8].

Detecting Mate

Some programs rely on pseudo-legal move generation, and find Checkmate if all those moves are in fact illegal after making and finding the "refutation" of capturing the king. At the latest, if no legal move was found, programs need the information whether the king is in check to decide about checkmate or stalemate score. Despite, most programs (should be) are aware of check in advance, and use special move generator(s) if in check or even in double check:

Double check
- Only King moves or captures
Single check
1. Capture the checking piece
2. King moves or captures
3. In case of distant checks, interposing a piece between the threatening sliding piece and the king

Publications

1952

Dietrich Prinz (1952). Robot Chess. Research, Vol. 6, reprinted 1988 in Computer Chess Compendium » Mate-in-two

1965 ...

George W. Baylor (1965). Report on a Mating Combinations Program. SDC Paper, No. SP-2150, System Development Corporation, Santa Monica, Calif. » Mater
George W. Baylor, Herbert A. Simon (1966). A chess mating combinations program. AFIPS Joint Computer Conferences, reprinted in Herbert A. Simon (1979). Models of Thought. Yale University Press, pp. 181-200, in David Levy (ed.) (1988). Computer Chess Compendium.
George W. Baylor (1966). A Computer Model of Checkmating Behaviour in Chess. in Adriaan de Groot, Walter R. Reitman (eds.) (1966). Heuristic Processes in Thinking. International Congress of Psychology, Nauka, Moscow
Vladimir E. Alekseev (1969). Compilation of Chess Problems on a Computer. Technical translation FSTC-HT-23-124-69, US Army, NTIS AD 689470 (Problemy Kibernetiki, 19, 1967)

1980 ...

John Birmingham, Peter Kent (1980). Mate at a Glance. Advances in Computer Chess 2, reprinted in Computer Chess Compendium
Max Bramer (1982). Finding Checkmates. Computer & Video Games, Spring 1982, pdf hosted by Mike Watters » Mater
Don Beal (1984). Mating Sequences in the Quiescence Search. ICCA Journal, Vol. 7, No. 3

1990 ...

Thomas Mally (1993). Matt in Wieviel? PC Schach 3/93 (German)

2000 ...

Vladan Vučković (2004). Realization of the Chess Mate Solver Application. Yugoslav Journal of Operations Research, Volume 14, Number 2, pdf
Fridel Fainshtein (2006). An Orthodox k-Move Problem-Composer for Chess Directmates. M.Sc. thesis, Bar-Ilan University, pdf
Fridel Fainshtein, Yaakov HaCohen-Kerner (2006). A Chess Composer of Two-Move Mate Problems. ICGA Journal, Vol. 29, No. 1, pdf
Ami Hauptman, Moshe Sipper (2007). Evolution of an Efficient Search Algorithm for the Mate-In-N Problem in Chess. EuroGP 2007, pdf

2010 ...

Azlan Iqbal (2010). Aesthetics in Mate-In-3 Combinations. Part I Combinatorics and Weights, ICGA Journal, Vol. 33, No. 3
Azlan Iqbal (2010). Aesthetics in Mate-In-3 Combinations. Part II Normality, ICGA Journal, Vol. 33, No. 4
Taichi Ishitobi, Alessandro Cincotti, Hiroyuki Iida (2013). Shape-Keeping Technique and Its Application to Checkmate Problem Composition. 2013 AIIDE Workshop

Forum Posts

1997 ...

Mate in 4 explanation by Howard Exner, CCC, October 07, 1997
Mate in 30 testposition for Rebel 9! by Jouni Uski, CCC, November 20, 1997 » Rebel
Mate in 18 moves? by Ed Schröder, CCC, January 09, 1998
Using too-shallow mate scores from the hash table by David Eppstein, CCC, July 05, 1998
Re: Using too-shallow mate scores from the hash table by David Eppstein, CCC, July 06, 1998
Re: Using too-shallow mate scores from the hash table by Don Dailey, CCC, July 07, 1998
Solve for Mate by Trefor Deane, CCC, July 11, 1998
Mate the Royal Couple by Hans Havermann, CCC, November 14, 1998
Estimated # of checkmate positions? by Jeff Anderson, CCC, July 07, 1999
Mate solvers... by Dann Corbit, CCC, September 07, 1999
Interesting mate test for hashing by Robert Hyatt, CCC, September 10, 1999 » Transposition Table
Is "Interesting mate test..." the longest ever thread.... by Tina Long, CCC, September 11, 1999

2000 ...

Mate in 1 - but Fritz 6 needs 1 hour!!! by Christoph Fieberg, CCC, August 10, 2000
What's the fastest mate-finder? by Michel Langeveld, CCC, August 27, 2000
Questions about Mate Searching by William Bryant, CCC, September 23, 2000 » Mate Search
Mate in 7 moves - diagram by Eduard Nemeth, CCC, September 27, 2000 » Zugzwang
Static Mate Detection by Gerd Isenberg, CCC, January 22, 2002 » Mate at a Glance
First mate in 2, then mate in 3 by Albert Bertilsson, CCC, March 03, 2003
Easy mate by Frank Phillips, CCC, September 13, 2003 ^[9]

2005 ...

Shortest ever mate? by Tord Romstad, CCC, October 30, 2005
The Code for the Rybka-Mate-Bug by Chrilly Donninger, CCC, December 13, 2005 » Rybka
Unusual Mate in 3 by Charles Roberson, CCC, March 02, 2006
Delayed-loss-bonus discussion goes here by Harm Geert Muller, CCC, September 28, 2007
mate detetion issue by Mike Adams, CCC, October 24, 2008 » Connect Four, Fail-Soft
How to check for checkmate/stalemate programmatically? by Valentin, Rybka Forum, November 22, 2008 » Stalemate
Draw by repetition when mate is possible by Mathieu Pagé, CCC, December 30, 2008 » Repetitions

2010 ...

Puzzle with mate scores in TT by Robert Purves, CCC, December 10, 2010 » Score, Transposition Table
Yet Another Mate Solving Test by Jouni Uski, CCC, January 14, 2011
Mate score in TT by Marco Costalba, CCC, December 28, 2011 » Score, Transposition Table
Checkmate In Zero by Christopher Conkie, CCC, January 02, 2013
To be, or not to be checkmated by Harm Geert Muller, CCC, April 18, 2014
Mate score from the transposition table by Evert Glebbeek, CCC, October 25, 2014 » Score, Transposition Table

2015 ...

Remember Leonid Liberman (author of LLCHESS)? by Dann Corbit, CCC, May 23, 2015 » Leonid's Positions
TT Mate scores by rgoomes, OpenChess Forum, February 10, 2016 » Score, Transposition Table
Funny mate in 6 by Sergei S. Markoff, CCC, February 17, 2016
Mate scores from IID by Matthew R. Brades, CCC, August 16, 2016 » Internal Iterative Deepening
Why do engines lack mate solving? by Rasmus Althoff, CCC, October 15, 2016 » Mate Search
Mate scores in TT (a new?... approach) by Vince Sempronio, CCC, April 09, 2018
Yet another Mate scores in TT thread by Andrew Grant, CCC, April 12, 2018 » Score, Transposition Table

Leonid's Positions

Mate in ...? by Leonid, CCC, February 12, 2000
Two mate positions to solve by Leonid, CCC, September 02, 2000
Two mate position to solve by Leonid, CCC, September 06, 2000
What shortest mate that you can find for this position? by Leonid, CCC, January 17, 2001
If you like to find a mate... by Leonid, CCC, January 18, 2001
If you want solve one mate... by Leonid, CCC, January 21, 2001
One easy mate to solve... by Leonid, CCC, January 22, 2001
One average mate position... by Leonid, CCC, January 23, 2001
If you like to solve easy forced mate... by Leonid, CCC, January 24, 2001
If you like to solve average mate position... by Leonid, CCC, January 25, 2001
If you like to solve real mate... by Leonid, CCC, January 27, 2001
If you like to solve mate from real game... by Leonid, CCC, January 28, 2001
If you like forced mate... by Leonid, CCC, January 30, 2001
Forced mate position to solve... by Leonid, CCC, January 31, 2001
If you like to solve a mate... by Leonid, CCC, February 01, 2001
Forced mate so solve... by Leonid, CCC, February 05, 2001
If you like to solve easy mate... by Leonid, CCC, February 08, 2001
If you like to solve a mate... by Leonid, CCC, February 09, 2001
If you like to crush easy mate... by Leonid, CCC, February 10, 2001
If you like to solve mate for light position... by Leonid, CCC, February 11, 2001
If you like to solve mate... by Leonid, CCC, February 14, 2001
If you like solving forced mate... by Leonid, CCC, February 15, 2001
If you like to solve one easy mate... by Leonid, CCC, February 16, 2001
Easy mate to solve... by Leonid, CCC, March 04, 2001
If you like to sove a mate... by Leonid, CCC, March 10, 2001
If you are ready to solve one mate... by Leonid, CCC, April 11, 2001
If you like easy mate... by Leonid, CCC, April 12, 2001
If you want to solve one mate... by Leonid, CCC, April 14, 2001
If you enjoy like me solving mates... by Leonid, CCC, April 16, 2001
Mate that every program will solve... by Leonid, CCC, April 17, 2001
One mate to solve... by Leonid, CCC, April 22, 2001
Mate to solve... by Leonid, CCC, April 23, 2001
Mate that every program will find by Leonid, CCC, April 26, 2001
Mate to solve for champions... by Leonid, CCC, April 29, 2001
One mate to solve for fittest programs by Leonid, CCC, May 04, 2001
Very easy mate to solve by Leonid, CCC, May 05, 2001
One mate to solve... by Leonid, CCC, May 06, 2001
Mate to solve in two flavous by Leonid, CCC, May 07, 2001
One mate to solve... by Leonid, CCC, May 08, 2001
One mate to solve... by Leonid, CCC, May 15, 2001
One very easy mate to solve by Leonid, CCC, May 21, 2001
One mate to solve... by Leonid, CCC, May 30, 2001
One mate to solve... by Leonid, CCC, June 02, 2001
Mate to solve for good program by Leonid, CCC, June 07, 2001
One mate to solve for Champion! by Leonid, CCC, June 16, 2001
One mate to solve by Leonid, CCC, July 17, 2001
One mate to sove for Champions! by Leonid, CCC, September 02, 2001
One mate to solve for Champions! by Leonid, CCC, October 02, 2001
A mate for Leonid by Sven Reichard, CCC, October 10, 2001
Try this mate by Leonid, CCC, October 16, 2001
Try solve this mate by Leonid, CCC, October 21, 2001
Try this moderate mate by Leonid, CCC, October 27, 2001
One easy mate by Leonid, CCC, November 04, 2001
Very easy mate to solve by Leonid, CCC, December 22, 2001
Find a mate by Leonid, CCC, August 03, 2002
One mate in 10 to solve by Leonid, CCC, August 10, 2002
One mate in 11 by Leonid, CCC, September 07, 2002
Try to solve mate by Leonid, CCC, September 14, 2002
Mate slightly harder by Leonid, CCC, August 25, 2003
Mate that should be easy by Leonid, CCC, October 19, 2003
Heavy mate position but easy to solve by Leonid, CCC, October 20, 2003
Mate to torture by Leonid, CCC, November 02, 2003
Try very easy mate by Leonid, CCC, November 04, 2003
Try to solve very populated mate by Leonid, CCC, November 05, 2003
Very easy mate by Leonid, CCC, November 06, 2003

External Links

References

^ Shannon Larratt - Fool's mate (2007) from Tableaux ayant pour sujet les échecs
^ In Loving Memory of Shannon Larratt 1:24, YouTube Video
^ Shannon Larratt is Zentastic › Blog archives, February 09, 2007
^ The Code for the Rybka-Mate-Bug by Chrilly Donninger, CCC, December 13, 2005
^ Evaluation: Aging - The Delay Penalty from Micro-Max by Harm Geert Muller
^ Re: Transposition Tables by Harm Geert Muller, CCC, September 26, 2007
^ Delayed-loss-bonus discussion goes here by Harm Geert Muller, CCC, September 28, 2007
^ Seeing a promotion, but not playing it... by Harm Geert Muller, CCC, January 24, 2010
^ Frank Phillips' KNNKP position revisited ... by Guy Haworth, CCC, September 18, 2003 » Endgame Tablebases

What links here?

Page	Date Edited
ACM 1974	Jan 19, 2018
Albert Bertilsson	Jun 6, 2017
Alybadix	Apr 26, 2016
BCP	Dec 30, 2015
Bionic	May 27, 2013
Check	Feb 1, 2018
Checkmate	Apr 13, 2018
Chess	Jan 21, 2018
Chess Champion Super System III	Sep 17, 2015
Chess Game	Mar 28, 2017
Chess Problems, Compositions and Studies	Feb 19, 2018
Chest	Mar 3, 2015
Chinese Chess	Jan 16, 2018
Coko	Jul 13, 2015
Composer	Sep 3, 2017
Connect Four	Jan 31, 2018
CXG Sphinx	Jun 23, 2017
Cyrus 68K	Jan 7, 2016
Dabbaba	Oct 21, 2014
Dictionary	Aug 24, 2017
Dietrich Prinz	Oct 14, 2016
DirGolem	Jun 5, 2016
Draw	Apr 14, 2018
Edwards' Tablebases	Sep 26, 2016
Endgame Tablebases	Mar 6, 2018
Fail-Soft	Jun 2, 2017
Fidelity	Jan 7, 2016
Fifty-move Rule	Aug 9, 2017
Futility Pruning	Aug 30, 2017
Genie	Feb 7, 2016
George Baylor	Sep 22, 2014
Gibbon	Dec 23, 2014
Giraffe	Jan 8, 2018
Gustav	May 14, 2016
Harm Geert Muller	Mar 31, 2018
Houdini	Apr 14, 2018
Interception	May 21, 2011
Internal Iterative Deepening	Feb 5, 2018
Jouni Uski	Sep 28, 2017
Kaissa	Apr 9, 2018
KBNK Endgame	Nov 26, 2016
King	Feb 26, 2013
Knightmate Chess	Apr 20, 2015
KnockOut	Sep 20, 2016
Knowledge	Jul 22, 2017
KRK	Nov 26, 2016
Leonid Liberman	May 23, 2015
LL Chess	May 23, 2015
Losing Chess	Sep 18, 2017
Matant	Aug 14, 2013
Mate at a Glance	Sep 24, 2014
Mate Distance Pruning	Jun 2, 2017
Mate Killers	Feb 4, 2017
Mate Search	Oct 22, 2016
Mate-in-two	Oct 14, 2016
Mater	Apr 26, 2016
Mathieu Pagé	Feb 14, 2018
Matthew R. Brades	Jun 9, 2017
Mini Chess	Jun 7, 2013
MLChess	Jan 17, 2017
Mop-up Evaluation	Nov 26, 2016
Null Move Pruning	Dec 2, 2017
Overloading	May 5, 2017
Papa	Jan 11, 2018
Paradise	Nov 19, 2014
Perft	Sep 26, 2017
Perft Results	Feb 10, 2018
Piece Drop	Feb 20, 2018
Plymate	Jan 7, 2016
Proof-number search	Jan 22, 2018
python-chess	Nov 4, 2017
Repetitions	Jan 16, 2018
Retrograde Analysis	Mar 21, 2017
RISC 2500	Jan 7, 2016
Rolf C. Smith	Aug 25, 2014
Score	Apr 14, 2018
SEX Algorithm	Nov 25, 2014
Stalemate	Feb 21, 2018
Tactics	Jan 12, 2018
Terminal Node	Nov 17, 2012
Thompson's Databases	Dec 24, 2014
Transposition Table	Apr 19, 2018
Vice	Mar 8, 2016
Win at Chess	Sep 25, 2017
Winglet to include	Apr 25, 2015
Zwischenzug	Jan 15, 2014

Up one Level

Combination

GerdIsenberg — Tue, 25 Oct 2016 20:34:29 GMT

Home * Chess * Tactics * Combination

		A Combination is a sequence of moves which uses tactical means and exploits specific peculiarities of the position to achieve a certain goal ^[1] . Combinatorial motives may include tactics like pins, discovered checks and attacks, double attacks, forks and so on. It often starts with a sacrifice or decoy, and leaves the opponent very few forced options to reply. The search routine of a chess program may take some plies to recognize an initial sacrifice pays off, to distinguish it from a blunder. Extensions are designed to recognize successful combinations earlier, often triggered by forced and often singular replies from the defending side. A so called Petite combination involves only a few moves ^[2] ^[3] .
Striking combination ^[4]

Publications

Jacques Pitrat (1976). Realization of a Program Learning to Find Combinations at Chess. Computer Oriented Learning Processes (ed. J. Simon). Noordhoff, Groningen, The Netherlands.
Jacques Pitrat (1979). A Program which Uses Plans for Finding Combinations in Chess. ICCA Newsletter, Vol. 2 No. 2
Jacques Pitrat (1980). The Behaviour of a Chess Combination Program using Plans. Advances in Computer Chess 2
Kevin Coplan (1982). A Special-Purpose Machine for an Improved Search Algorithm for Deep Chess Combinations. Advances in Computer Chess 3
Azlan Iqbal (2010). Aesthetics in Mate-In-3 Combinations, Part I Combinatorics and Weights. ICGA Journal, Vol. 33, No. 3
Azlan Iqbal (2010). Aesthetics in Mate-In-3 Combinations, Part II Normality. ICGA Journal, Vol. 33, No. 4

Forum Posts

What is a combination? Define it please! by Don Dailey, CCC, September 06, 1998

External Links

Combination (chess) from Wikipedia
Combination (disambiguation) from Wikipedia
Combo from Wikipedia
Improve Your Middle Game (Part 2 - Combinations) by Mark Weeks
The Chris Hinze Combination - Skyrider, from Sister Slick (1974), YouTube Video
feat. John Lee, Gerry Brown, Philip Catherine, Jasper van 't Hof, Rob Van Den Broeck, Jan Huydts, Robert Jan Stips, Henny Vonk

References

^ Harry Golombek (1977). Golombek's Encyclopedia of Chess. Crown Publishing, ISBN 0-517-53146-1, amazon.com
^ Chess Glossary - chess-poster.com
^ Chess Theory, Glossary P © Chess-Theory.com 2004-2009
^ Kāneʻohe Bay's Fighters Unlimited Boxing Team member Matthew Miller takes a hard hit from Palolo Boxing Club's Aaron Floyd. Miller was K-Bay's champion fighter Saturday during the boxing tournament held at Kahuna's Ballroom, by Megan L. Stiner, November 05, 2004, Striking combination from Wikipedia

What links here?

Page	Date Edited
Blockade	Oct 19, 2017
Blockade of Stop	Oct 11, 2016
Coko	Jul 13, 2015
Combination	Oct 25, 2016
Danny Kopec	Oct 1, 2016
Decoying	Jan 12, 2015
Deflection	May 21, 2011
Dictionary	Aug 24, 2017
Don Dailey	Dec 7, 2016
EtaBeta	Jan 7, 2016
George Baylor	Sep 22, 2014
Interception	May 21, 2011
Killer (NL)	Dec 15, 2017
KnockOut	Sep 20, 2016
Mater	Apr 26, 2016
Mephisto MM V	Sep 1, 2017
Pawns Breakthrough	May 4, 2014
Ruslan Hajiev	Oct 2, 2014
Sacrifice	Aug 10, 2017
Samiel	Oct 6, 2014
Stalemate	Feb 21, 2018
Tactical Moves	Sep 22, 2010
Tactics	Jan 12, 2018
Trajectory	Jan 3, 2015
Undermining	Jun 10, 2012
WCCC 2016	Sep 18, 2017
Win at Chess	Sep 25, 2017

Up one Level

Decoying

GerdIsenberg — Mon, 12 Jan 2015 21:28:26 GMT

See also

External Links

What links here?

Home * Chess * Tactics * Decoying

Decoying is a sacrificial chess tactic to force a valuable piece, most often the queen and/or the king to capture on a poisoned square, so that it becomes co-target of a double attack, often a knight fork, which finally results in a tangible gain of the whole combination.

External Links

What links here?

Page	Date Edited
Blockade	Oct 19, 2017
Blockade of Stop	Oct 11, 2016
Combination	Oct 25, 2016
Decoying	Jan 12, 2015
Deflection	May 21, 2011
Dictionary	Aug 24, 2017
Duck	Dec 12, 2016
Sacrifice	Aug 10, 2017
Tactics	Jan 12, 2018

Up one Level

Deflection

GerdIsenberg — Sat, 21 May 2011 08:55:17 GMT

Home * Chess * Tactics * Deflection

A Deflection is a chess tactic that forces an opposing piece (the defender) to give up the defence of an important square or line, exposing the king or a valuable piece. If the defender is member of one or more balanced defend and attack sets with same number of attacks and defends of respective critical squares, a deflection sacrifice, often attacking the defender by putting a piece of the same kind en-prise, might be crushing.

External Links

What links here?

Page	Date Edited
Combination	Oct 25, 2016
Deflection	May 21, 2011
Dictionary	Aug 24, 2017
Overloading	May 5, 2017
Sacrifice	Aug 10, 2017
Tactics	Jan 12, 2018
Undermining	Jun 10, 2012

Up one Level

Discovered Attack

GerdIsenberg — Mon, 08 Nov 2010 13:38:01 GMT

Home * Chess * Tactics * Discovered Attack

A Discovered Attack is a X-ray related chess tactic, revealed when one piece moves out of the way of a sliding piece ray, discovering an attack to squares, opponent pieces or the king, the latter case called a Discovered Check. Discovered attacks can be extremely powerful, as the piece moved can make a threat independently of the piece it reveals.

During move generation or move ordering, one may encourage discovering moves by considering origin squares attacked by an own sliding pieces, as well as the resulting attacking direction.

External Links

What links here?

Page	Date Edited
Battery	Jan 29, 2017
CAPS	Dec 23, 2017
Combination	Oct 25, 2016
Dartmouth CP	Jan 19, 2018
Dictionary	Aug 24, 2017
Discovered Attack	Nov 8, 2010
Discovered Check	Feb 1, 2018
Double Attack	Oct 22, 2014
Double Check	Apr 4, 2013
Move Ordering	Feb 27, 2018
Moves	Feb 19, 2018
Overloading	May 5, 2017
Sliding Pieces	Aug 3, 2017
Tactics	Jan 12, 2018
X-ray	Apr 12, 2017
X-ray Attacks (Bitboards)	Mar 31, 2015
Zwischenzug	Jan 15, 2014

Up one Level

Double Attack

GerdIsenberg — Wed, 22 Oct 2014 10:12:03 GMT

Home * Chess * Tactics * Double Attack

		A Double Attack attacks two or more pieces or important squares simultaneously with one move, either by forking with the moving piece, or at least by a single direct attack of the moving piece in conjunction with a discovered attack. The so called royal knight fork winning the queen is most important, but like other double attacks involving checks already covered by usual move selection heuristics.
Le duelliste à l'épée et au poignard ^[1]

Seeing Potential Forks

Seeing Potential Forks

Like a skewer or other tactical threats, it might be nice to determine the availability of forks in advance, to either try those moves early, to don't prune or reduce them, or even to try them at the horizon in quiescence search. As always, it depends on the board representation and the availability of appropriate data structures like Attack and Defend Maps, whether additional effort in determination of fork pattern, what kind of pieces to consider etc., makes sense and pay off.

Knight and Pawn

A common technique in bitboards to determine fork move target sets for respective pieces is to treat potential opponent targets as the kind of piece which may fork, and to pairwise intersect all their disjoint direction attacks, as demonstrated in knight forks.

Pawn fork targets have only two different and contact attacking directions. For instance, white pawn fork targets need the intersection of east and west black pawn attacks of all black pieces, excluding the guarding real black pawn attacks. If this resulting set intersects with white pawn push targets, white has likely (considering pins) one or more pawn forks.

Single pawn and knight forks are easy to determine with any board representation, since the patterns are simple. For knight forks one may rely on knight-distance of two, implying the precondition of same square color between all potential attacking targets and one own attacking knight.

Sliding Pieces

For sliding piece forks, Mailbox or 0x88 based board representations may rely on techniques as described in Intersection Squares, while it seems bitboards have an edge using attack set intersection of a pair of targets.

External Links

References

^ Jacques Callot - Le duelliste à l'épée et au poignard, 1621-1625, Source: Les Gobbi, Le duelliste à l'épée et au poignard : estampe / Jacques Callot, Bibliothèque nationale de France, Category:Jacques Callot from Wikimedia Commons

What links here?

Page	Date Edited
AI Chess	Jan 7, 2016
BigLion	Sep 28, 2016
Chenard	Sep 5, 2015
Combination	Oct 25, 2016
Dartmouth CP	Jan 19, 2018
Decoying	Jan 12, 2015
Dictionary	Aug 24, 2017
Discovered Attack	Nov 8, 2010
Double Attack	Oct 22, 2014
Double Check	Apr 4, 2013
Gibbon	Dec 23, 2014
Hanging Piece	Jan 14, 2017
Kaissa	Apr 9, 2018
Knowledge	Jul 22, 2017
Loose Piece	Jan 10, 2015
Moves	Feb 19, 2018
Paradise	Nov 19, 2014
Skewer	Oct 22, 2014
Tactics	Jan 12, 2018
Treebeard	Mar 25, 2015

Up one Level

Double Check

GerdIsenberg — Thu, 04 Apr 2013 13:36:31 GMT

See also

External Links

What links here?

Home * Chess * Check * Double Check

A Double Check is a X-ray related chess tactic where two pieces deliver check simultaneously, either most often by one direct check in conjunction with a discovered check, or in exceptional rare cases by two discovered checks after an en passant capture. Only king moves may legal in double check evasion, which is usually considered by a special case move generator even if not strictly legal.

External Links

What links here?

Page	Date Edited
Check	Feb 1, 2018
Checkmate	Apr 13, 2018
Checks and Pinned Pieces (Bitboards)	Aug 14, 2013
Dictionary	Aug 24, 2017
DirGolem	Jun 5, 2016
DiscoCheck	Jun 23, 2017
Discovered Attack	Nov 8, 2010
Discovered Check	Feb 1, 2018
Double Attack	Oct 22, 2014
Double Check	Apr 4, 2013
Lachex	Jan 7, 2016
Legal Move	Feb 16, 2017
Mater	Apr 26, 2016
Move Generation	Jan 29, 2018
Moves	Feb 19, 2018
Spector	Nov 11, 2016
Tactics	Jan 12, 2018

Up one Level

En prise

vincentlejeune — Tue, 11 Oct 2016 15:16:43 GMT

Home * Chess * Tactics * En prise

En prise (from French "can be taken") ^[1] describes a piece or pawn exposed to a material winning capture by the opponent. This is either a hanging piece, a not defended pawn ^[2] , a piece attacked by a lower valuable attacker, or a piece or pawn defended insufficiently. Any least valuable attacker (LVA) would gain a positive score from a static exchange evaluator on the target square, which also applies to a knight defended by a pawn and attacked by bishop and rook, where the majority of attackers and a least valuable attacker of similar value makes the knight en prise.

With pins, overloading, and other tactical motives in mind, whether keeping or putting a piece en prise is a blunder or a sacrifice is a matter of search, the latter may require some depth left to differentiate.

External Links

En prise - Glossary of chess from Wikipedia
en prise - Wiktionary
Earliest Occurrences of Chess Terms by Edward Winter
En Prise - Chess Basics
En prise from ChessBase News, April 13, 2012

References

^ Earliest Occurrences of Chess Terms by Edward Winter
^ The ambiguous term hanging pawns refers a duo of open and half-isolated pawns

What links here?

Page	Date Edited
CAPS	Dec 23, 2017
Captures	Oct 1, 2017
Deflection	May 21, 2011
Delicate Brute	Jun 7, 2016
Dictionary	Aug 24, 2017
En prise	Oct 11, 2016
Golch	Dec 7, 2017
Hanging pawns	Aug 5, 2015
Hanging Piece	Jan 14, 2017
Loose Piece	Jan 10, 2015
Mac Hack	Apr 20, 2018
Machiavelli	Jun 2, 2015
Mobility	Jan 17, 2018
Ostrich	Dec 28, 2017
Overloading	May 5, 2017
Pieces	Feb 19, 2018
Pin	Mar 7, 2017
Point Value	Mar 31, 2018
Querg	Dec 11, 2013
Sinobyl	Jul 3, 2014
Skewer	Oct 22, 2014
SOMA	Mar 25, 2015
Square Control	Sep 15, 2016
Tactics	Jan 12, 2018
Trajectory	Jan 3, 2015
Transposition	Jun 8, 2015
Undermining	Jun 10, 2012

Up one Level

Hanging Piece

GerdIsenberg — Sat, 14 Jan 2017 22:40:46 GMT

Home * Chess * Tactics * Hanging Piece

A hanging piece is an attacked piece not defended by own man exposed to capture. While hanging is often used synonymously with being en prise, the latter actually requires not necessary undefended, but also defended insufficiently. To avoid confusion with hanging pawns, which refer a duo of open and half-isolated pawns, undefended or loose pawns are therefor not called hanging. Loose pieces and undefended pawns, even if actually not attacked and en prise, may be considered in evaluation, specially if there are more than one or even two per side, and the opponent has forces and possibilities for double attacks and knight forks. Game phase, an exposed king and the presence of the opponent queen can be considered as well in that evaluation term.

Forum Posts

Evaluation in REBEL (hanging pieces) by Tony Werten, CCC, January 10, 2003 » Rebel
table-based SEE or "evaluation in rebel (hanging pieces)" by Martin Fierz, CCC, November 27, 2003 » Rebel, Static Exchange Evaluation
hanging pieces in rebel by Bernward Klocke, CCC, January 15, 2004 » Rebel
hanging piece at starting quiescence search - how to handle? by Reinhard Scharnagl, CCC, February 22, 2015 » Quiescence Search
hanging pieces by Alexandru Mosoi, CCC, Aug 21, 2016

External Links

Hanging - Glossary of chess from Wikipedia
Hanging Pieces by Roger McIntyre, Huntsville Chess Club
The Loose Piece from Chess Tactics Explained in English: Ward Farnsworth's Predator at the Chessboard
Herbie Hancock & The Headhunters - Hang Up Your Hang Ups, Ivanhoe Theater, Chicago, February 16, 1977, YouTube Video
Herbie Hancock, Jaco Pastorius, James Levi, Bennie Maupin

What links here?

Page	Date Edited
Bruja	Feb 3, 2015
Captures	Oct 1, 2017
chess22k	Apr 23, 2018
Cumulus	Jan 7, 2016
Demolito	Mar 1, 2018
Dictionary	Aug 24, 2017
DirGolem	Jun 5, 2016
Donna	Aug 17, 2017
En prise	Oct 11, 2016
Gibbon	Dec 23, 2014
Gogobello	Jul 30, 2017
Hanging pawns	Aug 5, 2015
Hanging Piece	Jan 14, 2017
Knight Pattern	Feb 23, 2015
Loose Piece	Jan 10, 2015
Martin Fierz	Apr 26, 2018
Now	Jan 7, 2016
Opponent Model Search	Aug 14, 2017
Overloading	May 5, 2017
Pieces	Feb 19, 2018
Quiescence Search	Aug 19, 2017
RDChess	May 3, 2013
Rebel	Feb 25, 2018
Reinhard Scharnagl	Apr 9, 2016
Rodent	Jan 11, 2018
Spector	Nov 11, 2016
Square Control	Sep 15, 2016
Static Exchange Evaluation	Dec 14, 2017
SuperChess	Dec 7, 2016
Tactics	Jan 12, 2018
Tony van Roon-Werten	Jan 14, 2017

Up one Level

Interception

GerdIsenberg — Sat, 21 May 2011 08:49:14 GMT

Home * Chess * Tactics * Interception

Interception or closing a line is a chess tactic similar or synonymous to Interference, with the aim to interrupt a defense trajectory of an opposing sliding piece, often a queen in conjunction with defending mate threats. The intercepting move, typically a threat by itself, has a negative SEE value, but its target square is at least one time defended by an other piece of the attacking side, so that the defending queen can not capture without losing material to perpetuate the defense, while opponent winning captures close the line to disconnect the queen from defense. Interception is the domain of the search, while such SEE losing interception moves might not be pruned near the tips.

External Links

What links here?

Page	Date Edited
Dictionary	Aug 24, 2017
Interception	May 21, 2011
Interference	May 20, 2011
Tactics	Jan 12, 2018
Trajectory	Jan 3, 2015

Up one Level

Overloading

GerdIsenberg — Fri, 05 May 2017 21:47:06 GMT

Home * Chess * Tactics * Overloading

Overloading is a chess tactic where a piece has more than one exclusive defending obligation. For instance, if the defending piece is member of two or more balanced defend and attack sets (equal number of attacks and defends) of their respective critical squares, the piece is likely overloaded, except for defending sliding pieces with both squares connected by a single move. Critical squares, attacked by the opponent, are either occupied by pieces from the defenders side, and/or otherwise mate threatening squares around the king or the backrank.

Despite tactics is the domain of search, and static evaluation of overloading pieces seems complicated considering tactical interactions and issues like pieces en prise or hanging, discovered attacks, checks, pins, Zwischenzug and counter attacks, some programs statically determine overloading pieces and other tactical motives for counting all kinds of obligations to consider their balance in nonlinear evaluation terms and/or controlling the search, quiescence search and their selectivity.

External Links

Overloading (chess) from Wikipedia
Chess Corner - Chess Tutorial - Overloading
Chess overloading from chessguru.net
Passport - Cross-Collateral (1975) ^[1], YouTube Video
lineup: Klaus Doldinger, Curt Cress, Wolfgang Schmid, Kristian Schultze

References

^ Cross-collateralization from Wikipedia

What links here?

Page	Date Edited
Attack and Defend Maps	Nov 5, 2016
BreakThrough	Nov 26, 2016
Deflection	May 21, 2011
Dictionary	Aug 24, 2017
En prise	Oct 11, 2016
Killer (NL)	Dec 15, 2017
Knowledge	Jul 22, 2017
Move Ordering	Feb 27, 2018
Overloading	May 5, 2017
Pieces	Feb 19, 2018
Tactics	Jan 12, 2018
Treebeard	Mar 25, 2015
Undermining	Jun 10, 2012

Up one Level

Passed Pawn

GerdIsenberg — Wed, 11 Oct 2017 19:22:33 GMT

Home * Evaluation * Pawn Structure * Passed Pawn

		A passed pawn, also called free pawn or passer, is a pawn with no opponent pawns in front on the same or adjacent files. In case of doubled pawns, it is wrong to score the back twin as passed, even if it meets the above conditions. Therefor, the passer requires his front span disjoint from all other pawns, as well as the front fill disjoint from opponent pawn attacks, which also excludes pawn levers ^[1]. In its simplest form, passed pawn evaluation assigns a bonus which increases as the pawn advances, often by dedicated piece-square tables. There are, however, different considerations to be taken into account, some of which are listed below.
Schachclub Freibauer Schöneberg ^[2]

Considerations

Please note that a hidden passed pawn is not a passer according to the above definition.

Forum Posts

1998 ...

Passed Pawn Evaluation by Stuart Cracraft, CCC, April 27, 1998
Passed pawn values by James Robertson, CCC, October 27, 1999

2000 ...

Passed Pawn Suite by Howard Exner, CCC, February 24, 2000 » Test-Positions
Intersting testposition: multiple passed pawns by Alexander Kure, CCC, March 23, 2003
passed pawn evaluation by macaroni, CCC, January 11, 2004

2010 ...

Passed Pawns (endgame) by Marek Kwiatkowski, CCC, May 07, 2010
An unstoppable passed pawn by Marek Kwiatkowski, CCC, June 11, 2010
Improving evaluation of passed pawns by Ben-Hur Carlos Vieira Langoni Junior, CCC, January 22, 2011 » Candidate Passed Pawn
passed pawn question by Alberto Sanjuan, CCC, August 02, 2013

2015 ...

The strongest passer by Lyudmil Tsvetkov, CCC, February 19, 2015
bad eval for passers ? by Daniel Anulliero, CCC, February 23, 2015
passed but doubled pawns by Jon Dart, CCC, June 15, 2015 » Doubled Pawn
Passed pawn detection in array based board representations by Shawn Chidester, CCC, September 20, 2015
Passed pawn evaluation by Daniel Mehrmann, CCC, December 13, 2015

External Links

References

^ passed pawn question by Alberto Sanjuan, CCC, August 02, 2013
^ Schachclub Freibauer Schöneberg e.V

What links here?

Page	Date Edited
AI Chess	Jan 7, 2016
Alarm	Jun 7, 2017
Alberto Sanjuan	Nov 3, 2014
Alex Kure	Aug 27, 2016
Amundsen	Sep 3, 2013
Amyan	Dec 10, 2013
Andscacs	Jan 16, 2018
Asymmetric evaluation	Nov 17, 2016
Backward Pawn	May 5, 2017
Ben-Hur Carlos Vieira Langoni Junior	Dec 17, 2013
Bishops of Opposite Colors	Aug 22, 2012
Bismark	Apr 22, 2015
Bison	Sep 29, 2016
Blockade	Oct 19, 2017
Blockade of Stop	Oct 11, 2016
Blockage Detection	Oct 19, 2017
Bobby	Jan 7, 2016
Bobcat	Jun 27, 2017
Brainstorm	Jun 24, 2017
Candidate Passed Pawn	Nov 11, 2017
Candidates (Bitboards)	Nov 11, 2017
Cheese	Feb 17, 2018
Chenard	Sep 5, 2015
chess22k	Apr 23, 2018
ChessBrainVB	Jun 24, 2017
Chexa	Feb 18, 2014
Chiron	Sep 24, 2017
Clarabit	Nov 3, 2011
Coiled	Mar 12, 2017
Comet	Jan 8, 2016
Connected Passed Pawns	Mar 27, 2015
Control of Stop and Telestop	Feb 26, 2013
CookieCat	Nov 15, 2016
Counter	Nov 13, 2017
CPW-Engine	Dec 31, 2014
Crafty	Jan 28, 2018
Cupcake	May 19, 2016
Daniel Mehrmann	Dec 13, 2015
Darmenios	Jan 7, 2016
Dartmouth CP	Jan 19, 2018
Defenchess	Mar 18, 2018
Delicate Brute	Jun 7, 2016
Demolito	Mar 1, 2018
Diablo	May 17, 2016
Dictionary	Aug 24, 2017
Djinn	Feb 8, 2016
Donna	Aug 17, 2017
Dorpsgek	Apr 2, 2018
Doubled Pawn	Mar 27, 2017
Endgame	Sep 18, 2017
Enigma	Feb 9, 2015
Eval Tuning in Deep Thought	Jun 7, 2016
Evaluation function draft	Jul 11, 2014
Evaluation Overlap	Jul 19, 2016
Exacto	Oct 3, 2015
Fortress (Engine)	Oct 19, 2017
Freyr	Mar 6, 2014
Garbochess	Sep 23, 2017
Gibbon	Dec 23, 2014
Gk	Oct 9, 2017
Gogobello	Jul 30, 2017
GopherCheck	Feb 3, 2017
Hakkapeliitta	Apr 26, 2016
Hanging pawns	Aug 5, 2015
Hidden Passed Pawn	Nov 11, 2017
ISA	Apr 2, 2018
IsiChess	Jan 7, 2016
Jumbo	Dec 19, 2017
Kaissa	Apr 9, 2018
King Centralization	Oct 30, 2017
King Pattern	Nov 15, 2013
King Pawn Tropism	Sep 1, 2014
Kiwi	Sep 2, 2016
Komodo	Mar 6, 2018
Ktulu	May 16, 2015
Late Move Reductions	Sep 25, 2017
Marvin	Feb 10, 2018
Maverick	Jan 7, 2016
MChess	Feb 26, 2018
Mephisto Dallas	Sep 1, 2017
Mephisto Lyon	Sep 1, 2017
Mobility	Jan 17, 2018
Nebula	Feb 7, 2015
Neurosis	Dec 23, 2017
NG-play	Feb 26, 2017
Nimzo	Dec 30, 2017
Nirvanachess	Sep 30, 2017
NoonianChess	Jan 7, 2016
OliThink	May 19, 2017
Open Pawns (Bitboards)	Aug 24, 2017
Oracle	Sep 4, 2016
Orion	Oct 15, 2017
Ostrich	Dec 28, 2017
Outside passed pawn	Jun 7, 2012
Passed Pawn	Oct 11, 2017
Passed Pawn Extensions	May 11, 2015
Passed Pawns (Bitboards)	Aug 23, 2010
Patzer	Apr 5, 2017
Pawn Endgame	Oct 11, 2017
Pawn Hash Table	Feb 1, 2018
Pawn Majority	Jun 8, 2012
Pawn Structure	Oct 2, 2017
PawnKing	Sep 5, 2014
Pawns Breakthrough	May 4, 2014
Peasant	May 21, 2015
Point Value by Regression Analysis	Aug 26, 2017
PolarChess	May 15, 2017
Prédateur	Nov 11, 2016
Protected Passed Pawn	Jun 7, 2012
RattateChess	Dec 2, 2014
Rebel	Feb 25, 2018
RedQueen	Nov 13, 2017
Réti Endgame Study	Feb 25, 2014
Rhetoric	Nov 15, 2017
Robocide	May 11, 2016
Rodent	Jan 11, 2018
Rule of the Square	Sep 6, 2014
RuyDos	Feb 17, 2018
Sayuri	Oct 1, 2017
Scorpio	Mar 28, 2018
SCP	Jun 16, 2016
Sentry	Nov 11, 2017
Shield	May 17, 2017
Simplex	Mar 6, 2016
Sloppy	Sep 17, 2016
Spector	Nov 11, 2016
Square Control	Sep 15, 2016
Stockfish	Apr 7, 2018
Tactics	Jan 12, 2018
Tarrasch Rule	Jun 2, 2014
Teki	Mar 29, 2018
Test-Positions	Feb 25, 2018
Texel	Oct 9, 2017
Thor's Hammer	Nov 23, 2013
Tucano	Dec 16, 2017
Unstoppable Passer	Jun 21, 2016
Vajolet	Jan 25, 2018
Vice	Mar 8, 2016
Wasp	Nov 24, 2017
WChess	Jan 7, 2016
Wing	Oct 26, 2017
Winglet	Apr 26, 2015
Witz	Nov 14, 2017
WyldChess	Mar 10, 2018
Xiphos	Apr 22, 2018
Xpdnt	Sep 13, 2015
Zeus RU	Jun 6, 2015
Zurichess	Mar 12, 2018

Up one Level

Pawns Breakthrough

GerdIsenberg — Sun, 04 May 2014 09:24:49 GMT

Home * Chess * Tactics * Pawns Breakthrough

Pawns Breakthrough,
a chess tactics to establish an advanced and likely unstoppable passed pawn by means of a sacrificial combination. In its most notable form a pawns breakthrough appears with opposing trios one rank apart already advanced on the other side of the board, for instance the white trio a5-c5 versus the black a7-c7. The combination starts with pushing the middle pawn which is now rammed with two levers. Black has two options to capture, and instead of a recapture finally yielding in an isolated ram, white sacrifices this pawn, and even offers a second one by pushing the closed pawn into a rammed lever.

Sample


1. b6		1... cxb {1... axb, 2. c6}		2. a6		2... bxc 3. axb or 2 ... bxa 3. c6

External Links

Passed pawns in the endgame | Passed pawn from Wikipedia

What links here?

Page	Date Edited
BreakThrough	Nov 26, 2016
Breakthrough (Game)	Aug 11, 2017
Dictionary	Aug 24, 2017
Passed Pawn	Oct 11, 2017
Pawn Endgame	Oct 11, 2017
Pawns Breakthrough	May 4, 2014
Tactics	Jan 12, 2018

Up one Level

GerdIsenberg — Tue, 07 Mar 2017 21:38:06 GMT

Home * Chess * Tactics * Pin

A Pin is a X-ray related situation where a sliding piece, a bishop, a rook or a queen indirectly attacks an opponent king or piece potentially en prise, shielded by another directly attacked opponent piece or pawn on the attacking ray. The direct attacked piece or pawn is then called pinned, and cannot move out of the line of attack, without leaving the indirectly attacked piece en prise or illegally its own king in check. All pieces except the king may be pinned. One tactic which takes advantage of a pin is called working the pin, where other pieces from the pinning piece's side attack the opposing pinned piece.

Types

Absolute Pin

The absolute pin is where the piece shielded by the pinned piece is the king. In chess programming, to detect absolute pins is necessary for legal move generation and may be considered in evaluation.

Partial Pin

A partial pin refers to (absolute) pins, where the pinned piece or pawn can move along the attacking direction, and may even capture the pinning sliding piece.

Relative Pin

A relative pin is where the piece shielded by the pinned piece is not the king, but either a more valuable than the pinned piece, or conditionally en prise.

Cross Pin

A cross pin describes the rare case, where one piece is pinned two more times in multiple directions simultaneously, most often one partial pin shielding the king and a relative pin shielding the queen. For instance in the otherwise harmless case of a partial pin of a bishop by a bishop, the bishop is also shielding a otherwise hanging queen by a queen, same may apply for rooks instead of bishops. Here the black rook on e4 is cross pinned and black will lose material and likely the game:

4k3/1p4pp/2p5/8/q3r2Q/3p3P/1P4PK/4R3 b - -

Of course with the white king on g1 or h1, things would be different. Such multiple issue tactics seems all the domain of the search and is hard to evaluate statically.

Situational Pin

This kind of relative pin is not about shielding own pieces, but important squares, for instance where an opponent rook may have a back rank mate. This kind of pins are usually only considered implicit by the search.

Considering Pins

Pinned pieces may be considered inside a chess program's move generation and evaluation.

Move Generation

Legal Move generation requires information about absolute pinned pieces, and their pinning direction to cover partial pins. Even non strictly legal move generation may reduce the number of generated illegal moves if considering absolute and partial pinnes, while ignoring the legality of En passant captures and castling.

Evaluation

Evaluation can take the restricted mobility of pinned pieces into account, and should consider the distance of the pinned pieces to its shielded king (or queen for relative pins) and whether it is on the own or opponent half of the board during the opening or middlegame. Some programs even calculate on working the pin, to look whether pinned pieces may further attacked by other pieces, especially pawns, for instance with bitboards whether they intersect opponent none-guarded pawn front attack spans and assign appropriate evaluation penalties.

Forum Posts

2000 ...

Question about the KnightCap find_pins function by Matthew White, CCC, July 14, 2003 » KnightCap
Evaluating Pinned Pieces by Tom Likens, CCC, May 19, 2004
SEE and pin detection by Dan Honeycutt, CCC, August 30, 2004 » Static Exchange Evaluation
Pin aware SEE by Dan Honeycutt, CCC, October 03, 2004
Bitboard of Pinned Pieces by Grant Osborne, CCC, July 24, 2008

2010 ...

LVA MVV with relative Pin by Clemens Pruell, CCC, February 16, 2011 » MVV-LVA
pinned pieces in eval by Pierre Bokma, CCC, October 01, 2011

External Links

What links here?

Page	Date Edited
0x88	Nov 28, 2016
AI Chess	Jan 7, 2016
Algebraic Chess Notation	Sep 25, 2017
Amyan	Dec 10, 2013
Attack and Defend Maps	Nov 5, 2016
Battery	Jan 29, 2017
Berkeley Chess Microprocessor	May 22, 2013
BigLion	Sep 28, 2016
Bison	Sep 29, 2016
CAPS	Dec 23, 2017
Check	Feb 1, 2018
Checks and Pinned Pieces (Bitboards)	Aug 14, 2013
Chenard	Sep 5, 2015
chess22k	Apr 23, 2018
ChipTest	Jun 19, 2016
Combination	Oct 25, 2016
Dan Honeycutt	Mar 13, 2014
Dartmouth CP	Jan 19, 2018
Dictionary	Aug 24, 2017
DirGolem	Jun 5, 2016
DisasterArea	Mar 27, 2017
Discovered Check	Feb 1, 2018
Double Attack	Oct 22, 2014
En passant	Jan 16, 2018
En prise	Oct 11, 2016
Evaluation of Pieces	Jan 8, 2018
Evaluation Overlap	Jul 19, 2016
Ghost	Feb 2, 2018
HpChess	Apr 2, 2015
Killer (NL)	Dec 15, 2017
KnightCap	Nov 6, 2016
Knowledge	Jul 22, 2017
Legal Move	Feb 16, 2017
Master	Dec 28, 2017
Mate at a Glance	Sep 24, 2014
Mobility	Jan 17, 2018
Move Generation	Jan 29, 2018
Move Ordering	Feb 27, 2018
Mr. Turk	Feb 21, 2015
MVV-LVA	Oct 26, 2017
Myopic	Nov 11, 2016
Obender	Apr 17, 2016
Ostrich	Dec 28, 2017
Overloading	May 5, 2017
Pin	Mar 7, 2017
Pseudo-Legal Move	May 23, 2015
RDChess	May 3, 2013
Rotated Indices	Oct 9, 2017
Sayuri	Oct 1, 2017
Scidlet	May 31, 2014
Skewer	Oct 22, 2014
Sliding Pieces	Aug 3, 2017
SOMA	Mar 25, 2015
Spector	Nov 11, 2016
Stalemate	Feb 21, 2018
Static Exchange Evaluation	Dec 14, 2017
Tactics	Jan 12, 2018
The switch Approach	Nov 5, 2010
Tom Likens	Mar 7, 2017
Treebeard	Mar 25, 2015
X-ray	Apr 12, 2017
X-ray Attacks (Bitboards)	Mar 31, 2015

Up one Level

Sacrifice

GerdIsenberg — Thu, 10 Aug 2017 17:30:01 GMT

Home * Chess * Moves * Sacrifice

A Sacrifice is a move offering a pawn or piece in the hope to gain tactical or strategical compensation. The opponent may be forced to accept the sacrifice or may otherwise have the option to decline it.

Chess programs usually need some remaining depth left from the horizon, to find the compensation and to distinguish sacrifices from blunders, either by forced tactical combinations or by positional long term damage considered by huge positional evaluation terms, most likely king safety related. If, during a game, the opponent offers an unexpected sacrifice, the program's time management should have the "take care" flag on. It might be a good idea to don't play too fast, happy with winning some material.

Quotes

^[1]

Mikhail Tal: There are two types of sacrifices: correct ones and mine
Rudolf Spielmann: A good sacrifice is one that is not necessarily sound but leaves your opponent dazed and confused
Savielly Tartakower: It's always better to sacrifice your opponent's men

Publications

Larry Harris (1975) The Heuristic Search And The Game Of Chess - A Study Of Quiescence, Sacrifices, And Plan Oriented Play. 4. IJCAI 1975, reprinted (1988) in Computer Chess Compendium
Jeng-Chi Yan, Shun-Chin Hsu, Jaap van den Herik (2005). The Sacrifice Move. ICGA Journal, Vol. 28, No. 4

Forum Posts

Positional sacrifice beyond our programs' understanding? by Dirk Frickenschmidt, CCC, May 31, 1998
Sacrifices by David Dahlem, CCC, August 24, 2011
"positional exchange sacrifice" examples by kgburcham, CCC, November 19, 2012
sacrificing by Stuart Cracraft, CCC, August 06, 2017

External Links

Sacrifice (chess) from Wikipedia
Sacrifice (disambiguation) from Wikipedia
Sacrifice from Wikipedia
Chaos in a Miniature by Edward Winter
Santana - Soul Sacrifice, Woodstock, August 16, 1969, YouTube Video
Carlos Santana, Gregg Rolie, David Brown, Michael Shrieve, Michael Carabello, José Areas

References

^ Chess - Wikiquote

What links here?

Page	Date Edited
Blockade	Oct 19, 2017
Blockade of Stop	Oct 11, 2016
Chess System Tal	Jan 13, 2017
Combination	Oct 25, 2016
Decoying	Jan 12, 2015
Deflection	May 21, 2011
Dictionary	Aug 24, 2017
En prise	Oct 11, 2016
Interception	May 21, 2011
Marek Kwiatkowski	Oct 22, 2017
Mater	Apr 26, 2016
Moves	Feb 19, 2018
MyChess	Dec 25, 2017
Pawns Breakthrough	May 4, 2014
Sacrifice	Aug 10, 2017
Sting	Mar 16, 2018
Tactics	Jan 12, 2018
Taktix	Sep 28, 2016
Time Management	Mar 20, 2018
Trapped Pieces	Oct 11, 2016
Win at Chess	Sep 25, 2017

Up one Level

Skewer

GerdIsenberg — Wed, 22 Oct 2014 13:50:23 GMT

Home * Chess * Tactics * Skewer

		A Skewer (thrust, reverse pin) is a X-ray related chess tactic where a sliding piece, a bishop, a rook or a queen double attacks two opponent pieces on the same ray similar to a pin, except the more valuable piece, often the checked king (absolute skewer), the queen or a rook (relative skewer) is attacked directly and compelled to move to parry the check or to avoid its capture, therefor exposing a less valuable piece which might be en prise. Some programs perform not only checks at the top of their quiescence search, but also attacks to the queen by either bishop and rook, or attacking a rook by a bishop, if an exposed piece behind might be en prise.
Disposición de los piqueros ^[1]

Composition

Following composition by Ado Kraemer and Walther von Holzhausen, Magdeburger Zeitung, 1930 ^[2] covers a skewer. The threat 1... b1=Q can be parried with the skewer b8=Q+, which safes white game and forces stalemate after 1.Ka8 Bh2 and sacrificing all pawns:

1K6/1P6/1kP5/3P4/4P3/5P2/1p4P1/6b1 w - -

External Links

References

^ Piquero - Wikipedia, la enciclopedia libre (Spanish)
^ Schachkomposition by Ado Kraemer and Walther von Holzhausen, Magdeburger Zeitung, 1930

What links here?

Page	Date Edited
AI Chess	Jan 7, 2016
Battery	Jan 29, 2017
Dictionary	Aug 24, 2017
Double Attack	Oct 22, 2014
Mate at a Glance	Sep 24, 2014
Paradise	Nov 19, 2014
Pin	Mar 7, 2017
Skewer	Oct 22, 2014
Tactics	Jan 12, 2018
X-ray	Apr 12, 2017
X-ray Attacks (Bitboards)	Mar 31, 2015

Up one Level

Stalemate

GerdIsenberg — Wed, 21 Feb 2018 17:13:20 GMT

Home * Chess * Draw * Stalemate

		Stalemate occurs if the side to move is not in check but has no legal moves. Stalemate results in a draw instead of losing the game if in check, and it is likely to occur in late endings only, where it is a regular resource that can enable the player with the inferior position to draw the game, i.e. in KPK or KQKP with rook pawn or bishop pawn on the seventh rank ^[1]. In others contexts, the word stalemate is also used for a metaphor when a conflict resolution seems difficult or impossible, i.e. a lose-lose situation.
Stephen Strait, Stalemate ^[2]

Detecting Stalemate

Like checkmate, stalemate is usually determined by the search if it turns out a node above the horizon becomes a terminal node without any further child nodes. It further depends on whether move generation relies on pseudo-legal moves or strictly legal moves.

Pseudo-legal move generation requires trying moves, to find at least one legal move or not, while legal move generation determines the information in advance. In late endings, static evaluation or interior node recognizer may support stalemate detection specially in quiescence search, for instance if there are no legal king moves, pawns are rammed or blocked and other pieces are pinned.

Desperado

Often there are tactical motives associated with so called Desperados, where pieces seem determined to give itself up to bring up stalemate if it is captured.

WMCCC 1993

At the WMCCC 1993 in Munich, round 8, The King found an amazing drawing combination in the game against Nimzo Guernica due to the rook desperados, to either give perpetual check forcing a threefold repetition, or to stalemate ^[3] ^[4]:

[Event "WMCCC 1993"]
[Site "Munich, Germany"]
[Date "1993.11.06"]
[Round "8"]
[White "The King"]
[Black "Nimzo Guernica"]
[Result "1/2-1/2"]
 
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Be7 8.Qf3 Qc7 
9.O-O-O Nbd7 10.Bd3 b5 11.Kb1 b4 12.Nce2 Bb7 13.Rhe1 h6 14.Bxf6 Bxf6 15.Qe3 Qc5 
16.Qg1 g5 17.Nb3 Qxg1 18.Rxg1 Bd8 19.Nd2 Nc5 20.Rgf1 O-O 21.Nd4 a5 22.fxg5 Bxg5
23.N4b3 Nxd3 24.cxd3 Rfc8 25.Nd4 d5 26.e5 a4 27.Nc2 b3 28.axb3 Ba6 29.Rf3 Bxd2 
30.Rxd2 axb3 31.Na3 Bb5 32.d4 Ba4 33.Rf6 Kg7 34.Rd3 Rc7 35.Rg3+ Kh7 36.Rgf3 Kg7 
37.Rf1 Rb8 38.R6f3 Rd8 39.h4 Rdc8 40.g4 Rb8 41.g5 hxg5 42.Rg3 Kh6 43.Rxg5 Be8 
44.Rgg1 f5 45.exf6 Bg6+ 46.Ka1 Rb4 47.h5 Bf5 48.Rf3 Rf7 49.Rfg3 Rxf6 50.Rh1 Be4 
51.Rhg1 Rf8 52.Rh3 Bf5 53.Rf3 Ra8 54.Rf2 Rxd4 55.Re2 Kxh5 56.Rh2+ Rh4 57.Rhg2 d4 
58.Rg5+ Kh6 59.Rh5+ Kxh5 60.Rg5+ Kh6 1/2-1/2


r7/8/4p3/5b1k/3p3r/Np6/1P4R1/K5R1 w - - 0 58		r7/8/4p2k/5bR1/3p3r/Np6/1P6/K7 w - - 2 61

nTCEC 1,2

Almost 20 years later, at TCEC Season 5, Stage 1, Spark, already with a huge winning score, became victim of a Delphil's desperado ^[5]

[Event "TCEC - Stage 1 - Season 5"]
[Site "http://www.tcec-chess.net"]
[Date "2013.09.02"]
[Round "3.13"]
[White "Delphil 3"]
[Black "Spark 1"]
[Result "1/2-1/2"]
 
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 Bc5 7.Nxe5 Nxe5 8.d4 Bxd4 
9.Qxd4 d6 10.f4 Nc6 11.Qd3 O-O 12.Bd2 Be6 13.Nc3 Bxb3 14.cxb3 Re8 15.Rac1 Nb4 
16.Qf3 Nc6 17.Be1 Nd4 18.Qd3 b4 19.Nd5 Nxd5 20.Qxd4 Nf6 21.Bh4 c5 22.Qd3 Re6 
23.Rc4 a5 24.f5 Re8 25.Rd1 Qe7 26.Bg3 Qb7 27.Bxd6 Rad8 28.e5 Rxe5 29.Bxe5 Rxd3 
30.Rxd3 Qe7 31.Re3 h6 32.h3 Nd7 33.Rce4 Nxe5 34.Rxe5 Qd6 35.Re2 Kh7 36.R5e4 Qd3 
37.Kh2 h5 38.g3 Kh6 39.g4 hxg4 40.hxg4 Kg5 41.Re1 a4 42.bxa4 c4 43.R4e2 Kxg4 
44.Rg1+ Kf3 45.Reg2 Qd6+ 46.Rg3+ Ke4 47.Rf1 Qd2+ 48.Rg2 Qh6+ 49.Kg1 Qe3+ 50.Kh2 
c3 51.Rff2 Kd4 52.Rf1 Qe4 53.bxc3+ bxc3 54.Rff2 Kc5 55.Kg3 Kb6 56.Rh2 Qxa4 
57.Rc2 Qe4 58.Rhf2 Ka5 59.Rfe2 Qd3+ 60.Kf4 f6 61.Rf2 Kb4 62.Rc1 Qd4+ 63.Kf3 Qc5
64.Kg2 Qd5+ 65.Kg3 Qe5+ 66.Rf4+ Ka5 67.Rc2 Qe1+ 68.Kh3 Qe3+ 69.Kg4 Kb6 70.Rff2 
Kc5 71.a4 Kb6 72.Rfe2 Qd3 73.Kf4 Ka5 74.Ra2 Qb1 75.Rf2 Qh1 76.Rfe2 Qd5 77.Kg4 
Qf7 78.Kf4 Qc7+ 79.Kf3 Qd6 80.Kg4 Qc5 81.Kf4 Qc4+ 82.Kg3 Qb3 83.Kg4 Qd5 84.Kf4 
Qd4+ 85.Kf3 Qh4 86.Rf2 Qh1+ 87.Kf4 Qe1 88.Kg4 Qe3 89.Kh4 g5+ 90.fxg6 Qg5+ 
91.Kh3 Qxg6 92.Rg2 Qh5+ 93.Kg3 Qg5+ 94.Kf3 Qh4 95.Ke3 f5 96.Rgc2 Qe4+ 97.Kf2 
Qd3 98.Kg2 f4 99.Kf2 Qg3+ 100.Kf1 f3 101.Rf2 Qg4 102.Rac2 Qh5 103.Kg1 Kxa4 
104.Ra2+ Kb4 105.Rfc2 Qg4+ 106.Kh2 Qh4+ 107.Kg1 Qg3+ 108.Kh1 Kc4 109.Rxc3+ Kxc3 
1/2-1/2


8/8/8/8/1k6/2p2pq1/R1R5/7K b - - 9 108 am Kc4		8/8/8/8/8/2k2pq1/R7/7K w - - 0 110

Forum Posts

2000 ...

Shortest Stalemate by Samuel Loyd by Ed Schröder, CCC, March 02, 2001
Nice Stalemate Trap by Tinker by Dieter Bürssner, CCC, October 29, 2001
Stalemate trap(SOS-Delfi) by George Lyapko, Winboard Forum, December 18, 2001 » Test-Positions, SOS, Delfi
How to handle EGTB stalemates by Tom Likens, CCC, March 02, 2003 » Endgame Tablebases

2005 ...

CQL - Stalemate with 2 pieces pinned by James Constance, CCC, July 17, 2005
Detecting stalemate with a pseudo-legal movegenerator? by Frederik Tack, CCC, November 11, 2005
How to check for checkmate/stalemate programmatically? by Valentin, Rybka Forum, November 22, 2008 » Checkmate

2010 ...

Patt-Bug, Junior 11.1a show mate and Ktulu 9.03 made patt! by Frank Quisinsky, CCC, March 23, 2010 » Junior, Ktulu
The unavoidable stalemate by Mike Scheidl, CCC, April 24, 2011
estimating the number of possible stalemates in perft(n) by Uri Blass, CCC, February 18, 2012 » Perft
Yace - Tinker 2001 -> 55.Rxg7?? by Vincent Lejeune, CCC, July 12, 2012 ^[6]
Draw by stalemate (Campbell, easy position for engines) by Jesús Muñoz, CCC, July 31, 2013 » Chess Problems, Compositions and Studies
stalemate detection and pruning by Jon Dart, CCC, September 22, 2013 » Pruning

2015 ...

Request for engines with modified stalemate values by Arno Nickel, CCC, April 16, 2015
static mate/stalemate detection? by Alexandru Mosoi, CCC, November 21, 2015 » Null Move Test-Positions, Zugzwang
How do you signal stalemate in iterative deepening? by Kenneth Jones, CCC, February 17, 2016 » Iterative Deepening
Surprisingly difficult stalemate problem (for some engines) by Juha Nieminen, CCC, May 16, 2016
Rabid rook escape by Henk van den Belt, CCC, June 23, 2016

External Links

Checkmate/Stalemate Scoring from Bruce Moreland's Programming Topics
Stalemate from Wikipedia
Stalemate: the long and the Short of it by H. Paul Lillebo, ChessBase News, August 2, 2014
Stalemate: the long and the Short of it – part 2 by H. Paul Lillebo, ChessBase News, August 23, 2014
Stalemate: the long and the Short of it (3) by H. Paul Lillebo, ChessBase News, September 22, 2014

References

^ Marcel Duchamp endgame "splits" engines / hash phenomenon by Kenneth Regan, CCC, February 19, 2018 » Chess Problems, Compositions and Studies, Marcel Duchamp, Transposition Table
^ Portraits by Stephen Strait
^ 12th World Microcomputer Chess Championship from the ICGA Tournament Database
^ Re: Your best bug ? by Ed Schröder, CCC, August 07, 2012
^ nTCEC - Stage 1 - Season 2
^ Nice Stalemate Trap by Tinker by Dieter Bürssner, CCC, October 29, 2001

What links here?

Page	Date Edited
Alybadix	Apr 26, 2016
Arno Nickel	Sep 25, 2015
Bestia	Jan 5, 2013
Charly	Jan 10, 2013
Check	Feb 1, 2018
Checkmate	Apr 13, 2018
Chess for Android	Mar 1, 2018
Chess Game	Mar 28, 2017
Chess Problems, Compositions and Studies	Feb 19, 2018
Chest	Mar 3, 2015
Chinese Chess	Jan 16, 2018
Composer	Sep 3, 2017
Contempt Factor	Mar 10, 2018
Delfi	Jan 7, 2016
Delphil	Sep 17, 2016
Desperado	May 19, 2017
Dictionary	Aug 24, 2017
DirGolem	Jun 5, 2016
Draw	Apr 14, 2018
Draw Evaluation	Mar 12, 2018
Endgame Tablebases	Mar 6, 2018
Fortress	Feb 1, 2018
George Lyapko	Jan 14, 2013
Gustav	May 14, 2016
Huberman	Aug 9, 2013
Interior Node Recognizer	Mar 12, 2018
Iterative Deepening	Jun 23, 2017
Jabba	Sep 10, 2016
Junior	Feb 27, 2018
Kaissa	Apr 9, 2018
KBNK Endgame	Nov 26, 2016
King	Feb 26, 2013
Knowledge	Jul 22, 2017
KPK	May 12, 2016
KRK	Nov 26, 2016
Ktulu	May 16, 2015
Losing Chess	Sep 18, 2017
Mate-in-two	Oct 14, 2016
Pawn Endgame	Oct 11, 2017
Peasant	May 21, 2015
Perft	Sep 26, 2017
Promotions	Jun 6, 2017
Pruning	Jan 1, 2018
python-chess	Nov 4, 2017
Repetitions	Jan 16, 2018
Score	Apr 14, 2018
Search with Random Leaf Values	Apr 23, 2018
Shatranj	Jul 26, 2017
Skewer	Oct 22, 2014
SOS	Apr 5, 2017
Spark	Oct 19, 2017
Stalemate	Feb 21, 2018
Tactics	Jan 12, 2018
Terminal Node	Nov 17, 2012
Test-Positions	Feb 25, 2018
Tom Likens	Mar 7, 2017
WCCC 2016	Sep 18, 2017
Winglet to include	Apr 25, 2015
WMCCC 1993	Dec 30, 2017
Wrong color Bishop and rook pawn	Oct 19, 2017
Zugzwang	Dec 8, 2017

Up one Level

Wikispaces : chessprogramming - items matching description

Battery

Table of Contents

Evaluation Considerations

See also

External Links

References

What links here?

Blockade

Table of Contents

Ambiguity

See also

Publications

External Links

References

What links here?

Check

Table of Contents

Kind of Checks

Single Check

Double Check

In Check Detection

By last Move

Attack Tables

On the Fly

Getting out of check

Double Check

Single Check

Perpetual Check

See also

Publications

Forum Posts

1997 ...

2000 ...

2005 ...

2010 ...

2015 ...

External Links

References

What links here?

Checkmate

Table of Contents

Mate Score

At the Root

Down the Tree

Detecting Mate

See also

Publications

1952

1965 ...

1980 ...

1990 ...

2000 ...

2010 ...

Forum Posts

1997 ...

2000 ...

2005 ...

2010 ...

2015 ...

Leonid's Positions

External Links

References

What links here?

Combination

Table of Contents

See also

Publications

Forum Posts

External Links

References

What links here?

Decoying

Table of Contents

See also

External Links

What links here?

Deflection

See also

External Links