Hydra

Hydra is a chess machine, designed by a team with Dr. Christian "Chrilly" Donninger, Ulf Lorenz, GM Christopher Lutz and Muhammad Nasir Ali. Hydra is under the patronage of the PAL Group and Sheikh Tahnoon Bin Zayed Al Nahyan of Abu Dhabi. The goal of the Hydra Project is to dominate the computer chess world, and finally have a widely accepted victory over humans.

Hydra represents a potentially significant leap in the strength of computer chess. Lorenz estimates its FIDE equivalent playing strength to be over ELO 3000, and this is in line with its results against Michael Adams and Shredder 8, the former micro-computer chess champion.

The Hydra team originally planned to have Hydra appear in four versions: Orthus, Chimera, Scylla and then the final Hydra version - the strongest of them all. The original version of Hydra evolved from an earlier design called Brutus and works in a similar fashion to Deep Blue, utilising large numbers of purpose-designed chips (in this case implemented as a field-programmable gate array or FPGA). In Hydra, there are multiple computers, each with its own FPGA acting as a chess coprocessor. These coprocessors enable Hydra to search enormous numbers of positions per second, making each processor more than ten times faster than an unaided computer.

Hydra currently runs on a 64 node Xeon cluster, with a total of 64 gigabytes of RAM. It evaluates about 200,000,000 chess positions per second, roughly the same as the much older Deep Blue, but with several times more overall computing power. Whilst FPGAs generally have a lower performance level than ASIC chips, Moore's law allows modern-day FPGAs to run about as fast as the older ASICs used for Deep Blue. The engine is on average able to evaluate up to a depth of about 18 ply (9 moves by each player), deeper than Deep Blue, which only evaluated to about 12 ply on average. Hydra's search uses alpha-beta pruning as well as null-move heuristics [1]. The extra search depth over Deep Blue is due to its use of more modern type B forward pruning techniques that are slightly less perfect, but generally play better due to the greater search depth these techniques permit.

The Hydra computer is physically located in Abu Dhabi, in the United Arab Emirates, and is usually played over a network link.