Ply (game theory) consists of one proposed move by the machine and one anticipated reply by the opponent"). In computing, the concept of ply is important because one ply corresponds to one level of the game tree. The Deep Blue chess computer which defeated Kasparov in 1997 would typically search to a depth of between six and sixteen plies to a maximum of forty plies in some situations. Ply (game theory) In two-player sequential games, a ply is one turn taken by one of the players. The word is used to clarify what is meant when one might otherwise say "turn". The word
Reversi game has been particularly attractive to programmers. Therefore, the best Othello computer programs have easily defeated the best humans since 1980, when the program "The Moor" beat the reigning world champion. In 1997, Logistello defeated the human champion Takeshi Murakami with a score of 6–0. Analysts have estimated the number of legal positions in Othello is at most 10, and it has a game-tree complexity of approximately 10. Mathematically, Othello still remains unsolved. Experts have not absolutely resolved what the outcome of a game will be where both sides use perfect play. However, analysis of thousands of high quality games