Computer beats human in strategy game Arimaa

A bot named Sharp defeated three strong human players in the strategy game Arimaa last Saturday in a showdown in which the best two-of-three was declared the winner. Developer David Wu will receive a $12,000 prize for this.

The challenge has thus become history. The game Arimaa is a board game that was developed in 2003 by Omar Syed after chess computer Deep Blue defeated chess world champion Garry Kasparov. The Challenge ran through 2020. The first person, organization or company to develop a program that would defeat three strong human players in three games could take home the prize money, provided the research paper was submitted. The program had to run on a normal computer without special hardware.

The game was developed in such a way that the rules of the game are very simple, but difficult to master by a computer. Only a normal chess board is needed to play it. The pieces are either silver or gold and consist of an elephant, a camel, two horses, two dogs, two cats and eight rabbits. Respectively, those pieces can be replaced by standard chess pieces.

The difficulty of the game is that there are more than 17,000 possible moves, compared to thirty in chess. Also, a maximum of four moves can be made per turn. All this with very simple rules, making it easy for humans, but difficult for computers. It also doesn’t make sense to put every possible hole in a computer, because there are over 64 million ways to start the game. Also, endgame databases are meaningless because the game can end with all the tiles on the board.