The StarTech Massively Parallel Chess Program Bradley C. Kuszmaul
[email protected] http://theory.lcs.mit.edu/Äbradley Laboratory for Computer Science Massachusetts Institute of Technology NE43-247, 545 Technology Square Cambridge, MA 02139 January 11, 1995 Abstract chess, the StarTech project has produced some interest- ing computer chess technology. This paper explains how The StarTech massively parallel chess program, running StarTech works and how it performs. on a 512-processor Connection Machine CM-5 supercom- The chess knowledge of StarTechÐwhich includes the puter, tied for third place at the 1993 ACM International opening book of precomputed moves at the beginning Computer Chess Championship. StarTech employs the of the game, the endgame databases, the static position- Jamboree search algorithm, a natural extension of J. Pearl's evaluation function, and the time-control strategyÐis Scout search algorithm, to ®nd parallelism in game-tree based on H. Berliner's Hitech program [BE89]. Hitech searches. StarTech's work-stealing scheduler distributes runs on special-purpose hardware built in the mid 1980's the work speci®ed by the search algorithm across the pro- and searches in the range of 100,000 to 200,000 positions cessors of the CM-5. StarTech uses a global transposition per second. Berliner provided me with an implementa- table shared among the processors. StarTech has an infor- tion of Hitech written in C (without any search extensions mally estimated rating of over 2400 USCF. except for quiescence with check extension) that runs at Two performance measures help in understanding the 2,000 to 5,000 positions per second.