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Houdini,
a chess engine by Robert Houdart, which appeared in 2010 as closed source engine, free for non-commercial use. In January 2011, Houdini 1.5 was leading Ingo Bauer's IPON rating list [1] . Houdini 2, released in September 2011, is commercial and bundled with a number of ChessOK products, such as Aquarium, Chess Assistant [2], and since December 2011, Chess King [3]. Houdini 1.5a remains available as a free download [4]. Houdini 3, released in October 2012, has further improved by more than 50 Elo points [5] . According to its author, Houdini 3 applies a accelerated principal variation search, also dubbed "Smart" Fail-High. If a different move becomes best at very high search depths at the root, re-searches to determine its exact score and the new principal variation are done faster due to a reduced search depth, presumably in conjunction with extensions along the PV [6] . Since November 2012, Houdini 3 is available as ChessBase engine [7] . Houdini 4, released in November 2013, was about 50 Elo stronger than its predecessor, and features 6-men Syzygy bases.
The Grim Game [8]

Houdini 5

Released about three years after the previous version, in November 2016, Houdini 5 is vastly improved being about 200 Elo stronger than Houdini 4. It has a completely rewritten evaluation with more aggressive king safety and sophisticated piece mobility, features a more selective search, exploring critical variations significantly deeper, and for hardware with multiple processors, Lazy SMP. Houdini 5 Pro supports up to 128 threads, up to 128 GiB of hash memory, large memory pages, NUMA-architecture, and Nalimov tablebases to find the shortest path to mate.

A development version of Houdini 5 qualified for TCEC Season 9 Superfinal, and even won the TCEC Season 9 Rapid tournament. The final release version of Houdini 5 is about 30 Elo stronger than the engine that played in the TCEC tournament so far. But that was apparently not enough for Stockfish 8 in long time control matches - Houdini 5 lost the 100 game Superfinal with 45½ - 54½.

Houdini 6

Released in September 2017, Houdini 6 again improved in search and evaluation to add another 50-60 Elo in strength, which roughly corresponds to doubling the computational power of the computer [9].

Houdini's Origin

Robert Houdart claims his engine is original [10] , and admits taking ideas from the open source programs Ippolit/Robbolito, Stockfish and Crafty [11] . Other programmers and forum members raised suspicions that Robert took ideas from the controversial Ippolit/Robbolito source code too literally as initial base of his program [12] [13] [14] [15] .

Sources of Inspiration

Robert Houdart on the origins of Houdini in CCC, June 08, 2010 [16]
From the start I have very clearly acknowledged the different sources of inspiration for Houdini (Ippo/Robbo, Stockfish and Crafty) and have shown every respect for the hard work of others, be it on my web site, in the readme file, or in this forum...

Houdini and the Ippo family have lots of high-level similarities, but zillions of low-level subtle differences.

Claims have been made that I "just changed a couple of resource strings", "made a cheap compile" or "grabbed some free code", but, in truth, none of you have any clue about the effort that was invested in Houdini.

It is funny that I would not be called a "real" chess engine author, when I am both a professional software developer and a reasonably strong chess player (peak 2280 rating), who has been writing chess engines for over 25 years now in a variety of programming languages.

It is sad that on the one hand you request that everybody demonstrates respect for the hard work of others, but on the other hand you seem to be unable to extend the same courtesy (or even the benefit of the doubt) to Houdini.

Material Table

The idea to index the material table in the same manner as Robbolito, with combined counters of queens, rooks, light and dark bishops, knights and pawns, and to calculate piece counters from that table-index by a sequence of mod/div operations by {2,2,3,3,2,2,2,2,3,3,9,9} might be considered obvious after studying the mentioned source code, and if applying that scheme, there is hardly anything to avoid a sequence of almost identical x86 machine code with same constants for reciprocal multiplication [17] .

Strelka 5

Robert Houdart on Strelka 5, December 04, 2011 [18]
Strelka 5 is Houdini 1.5 RE, not Houdini 2. I share your fears, any #1 engine will be RE'd in a matter of months. For Houdini 1.5 it's taken about 6 months.
Reply by Richard Vida [19]
You mean 6 months until Strelka has been released to public. You do not know how much time did Yuri Osipov spent on RE, neither when he did start his RE project. For me it took barely one week. As Milos S. pointed out [20] , you made RE very very easy because of starting your project from Robbolito codebase... Personally I see no problem with that (other than you not telling the truth).

Release Dates

  • Houdini 1.0 : May 15, 2010
  • Houdini 1.5 : December 15, 2010
  • Houdini 2.0 : September 01, 2011
  • Houdini 3 : October 15, 2012
  • Houdini 4 : November 25, 2013
  • Houdini 5: November 09, 2016
  • Houdini 6: September 17, 2017

See also


Publications

Harry Houdini

Chess Engine


Forum Posts

2010 ...

2011
2012
2013
2014

2015 ...

2016
2017

External Links

Chess Engine

Purchase

Interviews

Reports

Rating Lists


Harry Houdini


References

  1. ^ IPON-Rating-List Archive 2009/2010/2011 by Ingo Bauer
  2. ^ Houdini 2 Aquarium products family has been released!, ChessOK, October 07, 2011
  3. ^ Chess King Released, ChessOK, December 14, 2011
  4. ^ Re: Houdini 2 is released by Robert Houdart, CCC, September 02, 2011
  5. ^ IPON-Rating-List, 2012.10.17 by Ingo Bauer
  6. ^ Re: Houdini 3 reducing the depth feature by Robert Houdart, CCC, October 19, 2012
  7. ^ Houdini 3 Standard multiprocessor version, ChessBase Shop
  8. ^ The Grim Game a 1919 silent film starring Harry Houdini
  9. ^ Houdini Chess Engine
  10. ^ Re: Why Is Houdini Not Entered In The WCCC?? by Robert Houdart, Open Chess Forum, August 04, 2010
  11. ^ Houdini Chess Engine - Acknowledgements
  12. ^ Re: Why Is Houdini Not Entered In The WCCC?? by kingliveson, Open Chess Forum, August 09, 2010
  13. ^ Re: Why Is Houdini Not Entered In The WCCC?? by Robert Houdart, Open Chess Forum, August 10, 2010
  14. ^ Re: Computer Chess Biggest Liar by kingliveson, OpenChess Forum, October 11, 2011
  15. ^ Re: Interesting poll by Rebel, Rybka Forum, July 15, 2012
  16. ^ Re: Purpose of Chess Engine Origins forum is...? by Robert Houdart, CCC (Computer Chess Club: Engine Origins, requires registration), June 08, 2010 in a reply to Jeremy Bernstein
  17. ^ Houdini - a cheap compile of Ippo/Robo by Lance Perkins, CCC - Computer Chess Club: Engine Origins, May 29, 2010 (requires login)
  18. ^ Re: Komodo 4 on long time control by Robert Houdart, CCC, December 04, 2011
  19. ^ Re: Komodo 4 on long time control by Richard Vida, CCC, December 04, 2011
  20. ^ Re: Lazy eval - test results by Milos Stanisavljevic, CCC, December 01, 2011
  21. ^ Jean Eugène Robert-Houdin - Wikipedia
  22. ^ Part 1 covers Houdini, Rybka, Komodo, Stockfish, Critter, Naum, Chiron and Spike
  23. ^ Arpad Elo - Wikipedia
  24. ^ Houdini 5 to participate in TCEC Season 9, Chessdom, April 13, 2016

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