AlphaZero, Stockfish 10 en Komodo 12.2.2

AlphaZero, Stockfish 10 en Komodo 12.2.2

NM HanSchut

At the beginning of December Stockfish 10 was released. Stockfish has won the last three unofficial world championships for chess engines (TCEC) and confirmed its dominant position by also winning the chess engine tournament at recently. Stockfish 10 leads the CCRL 40/40 rating list with a rating of 3485 ahead of Komodo 12 and Houdini 6 with 3396 and 3394 respectively. Stockfish 10 is about 50 points stronger than Stockfish 9 and 100 points better than Stockfish 8.

Stockfish 9 won TCEC (among other things) by increasing the ‘contempt' parameter to 20. This parameter is an indication of how much risk a chess engine takes to win by striving for unbalanced positions. In Stockfish 10 the contempt factor is now standard set at 24, in Komodo at 16 and in Houdini at 20. GM Larry Kaufman, developer of Komodo, recommends raising the contempt factor against grand masters to 50 and against masters even further to 75!

Komodo, which is now part of, released version 12.2.2 in November. The biggest progress in Komodo 12.2.2 is in a special option: Monte Carlo Tree Search. The Komodo team, inspired by LeelaZero and AlphaZero, built this technique as a special option into their chess engine and version 12.2.2 MCTS is about 200 points stronger than version 12.0 MCTS. The rating of Komodo 12.2.2 MCTS is estimated at around 3300. I believe that the Komodo - MCTS engine provides an interesting second opinion to the traditional alpha-beta search based engines.

Last week, Google Deepmind published an article in Science about AlphaZero. The team has repeated the match with Stockfish 8 and addressed the heavily criticized uneven hardware conditions of the previous match. The hardware was still not equal but also cannot be the same: Stockfish runs on CPUs and AlphaZero on Google's TPUs. This time AlphaZero won 574.5 - 425.5 from Stockfish 8. This score of 57% corresponds to a rating difference of 50 points. Considering that Stockfish 10 is about 100 points stronger than Stockfish 8 ,this margin is not overly impressive. Of course it remains a unique and very interesting approach and furthermore it is mentioned in the Science article that AlphaZero also beat Stockfish 9 with 'large margins'. You can download the article the Science article here: AlphaZero Science Article The programmer-collective of Leela, who is building an engine based on the AlphaZero concept of self learning, has received a lot of new information through the latest publication of Google Deepmind and is using that to direct the further development of Leela now: See AlphaZero learnings for Leela

Finally, two beautiful moments from the match between Alpahzero and Stockfish 8. In both games, the game was started with an opening selected by Jeroen Noomen for the TCEC super final in 2016. The first one is a Dutch Leningrader, the second one an ultrasharp Bg5 - Najdorf.

Please have a look at AlphaZero's long term piece sacrifice to gain access to White's king.

AlphaZero lost a crucial tempo in this Bg5-Najdorf and is now with it's back against the wall.
Have a look at AlphaZero's creative defense: 26... Rxa2 followed by 31... a3 32... a2 and 33... Nd5