During my brief stint in playing with MCTS I also tried to implement transpositions. I read somewhere (about MoGo I think) that it would gain about 100 ELO points. But I didn't see any gain at all. David Fotland told me he used it and it did work for him.
Possibly my idea how to do it were plain wrong. I never had time to look into it very carefully. What I tried to do was creating a hash-table next to the tree. The hash-table contained lists of positions that were identical but with different positions in the tree. So a hash-table of lists. When updating the win-rate in the tree, I wouldn't just go up the one path, but up multiple paths when there were transpositions (taking care of loops). Basically the tree had become a graph. What I saw was a small gain for small number of nodes ( a few K), and worse results the larger the number of nodes became to the point it was a negative contribution. Mark _______________________________________________ Computer-go mailing list [email protected] http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
