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
Deep Blue versus Garry Kasparov the only game in the match that Black won. "February 17". The sixth game was an illustration of just how badly computers can play in some positions. Employing anti-computer tactics and keeping the focus of the game on long-term planning, Kasparov slowly improved his position throughout the mid-game while Deep Blue wasted time doing nothing. By the end of the game, Deep Blue's pieces were crammed into its queenside corner, with no moves to make aside from shuffling its king. Kasparov had all the time in the world to finish the rout. Kasparov's next move would probably have been 44.Qe7