Grouping Nodes for Monte-Carlo Tree Search
Jahn Takeshi Saito, Mark H. M. Winands, JOS W. H. M. UITERWIJK, H.J. van den Herik · Research Publications (Maastricht University) · 2007
Abstract. Recently, Monte-Carlo Tree Search (MCTS) has substan-tially contributed to the field of computer Go. So far, in standard MCTS there is only one type of node: every node of the tree represents a sin-gle move. Instead of maintaining only this type of node, we propose a second type of node representing groups of moves. Thus, the tree may contain move nodes and group nodes. This article documents how such group nodes can be utilized for including domain knowledge to MCTS. Furthermore, we present a technique, called Alternating-Layer UCT, for managing move nodes and group nodes in a tree with alternating layers of move nodes and group nodes. A self-play experiment demonstrates that group nodes can improve the playing strength of a MCTS program. 1