Ensemble UCT Needs High Exploitation

TL;DR

This paper explores how increasing exploitation in Ensemble UCT improves performance, especially in small search trees, which is significant for enhancing large-scale parallel MCTS applications.

Contribution

It demonstrates that higher exploitation levels in Ensemble UCT lead to better results in small search trees, informing optimization strategies for parallel MCTS.

Findings

Higher exploitation improves small search tree performance

Ensemble UCT benefits from increased exploitation levels

Results support tailored exploitation-exploration balance in MCTS

Abstract

Recent results have shown that the MCTS algorithm (a new, adaptive, randomized optimization algorithm) is effective in a remarkably diverse set of applications in Artificial Intelligence, Operations Research, and High Energy Physics. MCTS can find good solutions without domain dependent heuristics, using the UCT formula to balance exploitation and exploration. It has been suggested that the optimum in the exploitation- exploration balance differs for different search tree sizes: small search trees needs more exploitation; large search trees need more exploration. Small search trees occur in variations of MCTS, such as parallel and ensemble approaches. This paper investigates the possibility of improving the performance of Ensemble UCT by increasing the level of exploitation. As the search trees becomes smaller we achieve an improved performance. The results are important for improving the performance of large scale parallelism of MCTS.