Using partial tablebases in breakthrough

Abstract

In the game of Breakthrough the endgame is reached when there are still many pieces on the board. This means there are too many possible positions to be able to construct a reasonable endgame tablebase on the standard 8×8 board, or even on a 6×6 board. The fact that Breakthrough pieces only move forward allows us to create partial tablebases on the last n rows of each side of the board. We show how doing this enables us to create a much stronger MCTS based 6×6 player and allows us to solve positions that would otherwise be out of reach.