Hydra (chess)

Hydra is a chess computer that will be developed by the Austrian Christian " Chrilly " Donninger, the German Ulf Lorenz and Christopher Lutz and the company PAL Computer Systems from Abu Dhabi.

History

A precursor of the program was called Brutus and was given by the company ChessBase in order. After the disappointing performance of an early version in the World Computer Chess Championship 2003 in Graz ChessBase did not pursue the project, because there is no more exploitation was seen. The Hydra Team succeeded then, with the company PAL computer system of the United Arab Emirates to find a new financial backer.

Achievements

The partially new, partially refined program Hydra hit 2004 more times world computer chess champion Shredder in a competition in Abu Dhabi with 5,5:2,5. In the same year, the program achieved when comparing the fight against players of the world leaders in Bilbao 3.5 points from four games. In June 2005 Hydra succeeded in London with 5.5 to 0.5, a surprisingly high competition victory over the English world -class player Michael Adams. Hydra has so far never been beaten by a human chess player in a tournament game (August 2006). Only in correspondence chess lost the 2005 program a match against the Berlin Correspondence Chess Grandmaster Arno Nickel with 0,5:2,5. Also used was Hydra in Freestyle chess, an online damage chart, is allowed in the analysis supported by computer. His owners from Abu Dhabi, who performs under the pseudonym Zorchamp, played with Hydra in three tournaments between 2005 and 2006, scoring varying degrees of success. Most recently, he failed in June 2006, the final round qualifying, after he won in April 2006, the second PAL / CSS Freestyle Tournament. The developers gave in 2005 a playing strength of over 3000 Elo points to.

Hardware

Hydra consists of a running Linux computer cluster of currently 32 Intel Xeon processors that generate the search tree, and 32 FPGA cards that make the evaluation of positions and report back to the program. The most sensitive part of Hydra's search algorithm runs distributed on the mentioned Xeon processors, which are interconnected by a Myrinet high-speed network. Each processor uses its own FPGA board, and the flow of the distributed algorithm is essentially as follows: One of the processors receive the current chess position and starts a sequential alpha-beta search. Send the other processors work requests randomly around the net, and when a processor, who is working already sense the current chess problem, such captures a request, it is a sub-problem of his own ( sub-) problem from. With the help of a tricky messaging system between the processors, the work to be performed is dynamically balanced and there is only a low search overhead. After a while, then all processors have to do something meaningful, and each individual processor rated chess positions in its search tree with the help of his FPGA " coprocessor ". A Hydra processor generates approximately 100,000 small Search on a FPGA board per second.

The advantage of the FPGA board itself is that complex knowledge-based scoring function can be implemented without affecting the search speed significantly. Currently, the program can scan about 200 million positions per second and rate. This makes it about 100 times faster than software chess on a standard PC. The following figure shows a schematic representation of the Hydra hardware.

Opening library

For the opening book of the Hydra German Grandmaster Christopher Lutz is responsible. Unlike other programs whose opening repertoire based on played by chess masters games, it is not very extensive, as the program can calculate the often better moves independently.