The Week in Chess

Friday, May 10, 2013

Houdini 3 Defeated Stockfish 130425 at TCEC Superfinal Live Tournament

Finally, after 2 weeks of intense 48 games match between Houdini and Stockfish in the Superfinal Live Tournament, it was won by the chess engine with the number 1 rating in all Chess Engines Rating List.

Houdini won the match with a score of 6 wins, 4 losses and 38 draws. It was a very close match where the score was tied up to round 36. Some spectators were anticipating of a draw score and looking forward to the tie break. Eventually, Houdini broke the tie in round 37, held it and then scored the second point in the final game. It was a suspense from start to finish because everybody were kept guessing about the result and it was only known in the last round!

Recent statistics from the chess engines rating list sites are in favor for Houdini to win the match. My straightforward forecast that Houdini will win based on statistics became true.  Random luck is minimized at relatively long number of games and so the stronger one will usually prevail.

There was one factor that almost killed Houdini. It was the feature that allow chess engines to be substituted with a newer stronger version after each stage in the tournament. Stockfish was able to take advantage of this feature three times while Houdini was stuck with the original entry. Stockfish got stronger with each substitution, and probably the latest version called Stockfish 3 could upset Houdini had it came earlier in the match.

The TCEC chess tournament was a resounding success.  Congratulations to Martin Thoresen, the main organizer of the tournament.  Congratulations also goes to Robert Houdart for his mighty Houdini 3 that won the tournament and ruled the rating lists.

Many people has benefited from this rare elite tournament, especially the chess engine authors who saw the strengths and weaknesses of their chess engines during the matches.  They will all try to fix the shortcomings and then one day come together to try their luck once again.

Perhaps, the tournament is a warning signal for Houdini not to rest on its laurels. If +Robert Houdart will stick on his commercial obligations of not releasing frequently, he might find that Stockfish will be number 1 in the rating list before the next TCEC tournament season begins.


  1. Hi
    Do you think Stockfish will benefit if HT is enabled ( unlike the case with Houdini 3 ) ?

  2. I can't definitely give a correct answer because I don't have a CPU with multi-threading capability. There is no great news with hyper threading on Stockfish.

    However, according to Lucas Cimitotti, the man who built the monster Rybka cluster says "Hyperthreading sucks for chess - you should switch it off.". You may find this at

  3. John, I conducted some additional testing to follow up on your article about Stockfish "killed while sleeping on threads" and published them at
    Basically, yes, on some hyperthreaded systems (like mine), it is possible to get an illusion that Firenzina is stronger than Stockfish 3 by keeping SF3's Using Sleeping Threads option OFF (which is the default). However, the illusion is broken by turning Using Sleeping Threads ON, for both 8 threads and 4 threads.

  4. Dmitri,
    I read the post you published. Thank you for the confirmation that Sleeping Threads option when OFF is not recommended for Stockfish.


Chessdom News