i meant to pharase my question "what are the possible number of moves in a single chess game"?

Answer 1

This is an interesting question. I don't know the answer, but as I explain below, I think the range is 2 to 6,350.

1. As somebody said, at the lower end, I think there is a two move (ie two moves for each player) game that ends in checkmate. I suppose you could resign earlier, but leave that aside.

2. Whether the game can go on infinitely has some interesting mathematical importance. In game theory, it has been proven that a finite game of perfect information with no chance has an equilibrium in pure strategies. Translating to chess, it means that the game has an ending value, win, lose or draw, which neither player can better. (For example, by playing correctly in tac tac toe, either player can guarantee a draw.) So, if Chess is finite, then sufficiently bright players would have a game as boring as tic tac toe, which always ended with a white win, a black win or a draw. In practice, nobody is going to get that good, because the number of possible game paths is too big, so proving a result is an equilibrium ought to remain impossible. But the question remains, is chess finite?

3. I think it is. In the official rules for chess (FIDE rules?) was a rule that said the game may be ended in a draw by either player if 50 moves went by without a piece being taken or a pawn being moved. This is interesting. It moves the game forward because both kinds of move are irreversible. If a pawn moves, it can't move back. If a piece is taken, it is gone. Therefore, after at most 50 moves, you can guarantee that a board position won't be repeated.

Calculating ... there are 32 pieces on the board, but two are kings which can't be taken. There are 16 pawns each of which can make six moves at most before promoting. 30+6x16=126 moves that can stave off the draw. To maximise the length of the game, you'd have to make 49 1/2 vapid other moves, avoid mates and stalemates, pawn moves and takings and then make one of the 126 qualifying pawn or taking moves. After all of the pawn and taking moves are exhausted, the game would last at most another 50 moves. So the game ought not to be able to last longer than 127x50, or 6,350 moves without either player being able to force a draw.

Now it could be that even though both players could force a draw, neither would and they would just keep moving. But from a game theory standpoint, I don't believe that would alter things. If you have a situation where either player could force a draw after moving, in practice they would have to fail to spot a mate in one to do worse than a draw. That is not going to be an equilibrium strategy, since it is worse than forcing the draw. Still, I guess you could keep going in a loop. I shall have to look this up.

How's that!

Answer 2

Sorry mate...it still depends whether you mean the least possible moves or the most possible....and there is still no real answer.

It depends how evenly the players are matched. If one is very good and the other isn't, a game could be all over in about 5 moves. If they are as good as each other...a game could last for hours with lots of moves.

Answer 3

least possible number of moves in chess 4 checkmate is 4

Answer 4

Your question is really weird. If you mean the most possible moves it can theoretically last forever. If you mean the least possible moves it's two each player.