Comparison of Expectimax and Monte Carlo algorithms in Solving the online 2048 game

Abstract

In this work, two search algorithms Expectimax and Monte Carlo Tree Search (MCTS) were developed to solve the well-known “2048" puzzle online-game and compare their results. In both cases, five heuristics were employed to obtain favorable tile positions within the game. These heuristics were combined to maximize the game-score in all possible board positions. As a result, the game-score, the maximum value of tile obtained, and the computing time employed in solving the game are shown. In addition, the efficiency of each algorithm and its sub-cases are presented. This research concludes by arguing that Monte Carlo Tree Search was more efficient in higher score than Expectimax algorithm, although in a longer time. Increments in level of depth-search in Expectimax and number of moves in MCTS do not necessarily resulted in obtaining higher score.

Keywords

• 2048 game
• Expectimax algorithm, Monte Carlo algorithm
• heuristics