Experiments With a Fully Distributed Chess Program

We present some of the recent results of the distributed chess program ZUGZWANG. As pointed out earlier in FMM90] we use an algorithm with very good load balancing properties. Our algorithm enables us to use a stronger version of the Young Brothers Wait Concept. This stronger version is closely related to the idea of the Delayed Branching Scheduling Strategy of Hsu90] for a distributed game tree searching program. In addition we analyze the costs and gains of a distributed transposition table. This analysis indicates that a distributed transposition table has large advantages compared to a local or global one as long as fast message routing is guaranteed. We obtained a speedup of 126 running our distributed algorithm with 256 processors at tournament speed.