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 (video game) deep. Alone, players control the Earth's only defense against the attack, the A.N.G.E.L. Fish Attack Sub. "Deep Blue" is a basic horizontal scrolling shooter: players collect power-ups and different weapons to fight numerous enemies. The screen scales up and down allowing more vertical space. The game features a single life; the Angel Fish can take a lot of hits before it is destroyed, and even regenerates over time. Damage levels are represented by the color of the ship's 'eyes': they start out a solid blue, but when damaged, the eyes blink blue until going to green, then yellow, then red.