I have 5 pieces left and my opponent only has his king. It is my opponent's turn and his king is not in check but everywhere his king moves is checkmate. Who wins?
When it is your opponent's turn to move and none of your opponent's pieces can move other than his king, and if the king moves or captures your piece, it will be under check, then this type of position is called as stalemate and the result will be a draw.
- Simple one with just 3 pieces on Board (Black To Move):
Here, Black king has nowhere to go, the h8, h7, g7, f8 square is controlled by the Queen and the f7 square is controlled by the King.
- Another position of stalemate with few pieces (Black To Move):
Black has 2 pawns and his King. His pawns cant move forward or capture any pieces and his King cant move anywhere as its surrounding is controlled by the pieces as shown in the image.
- A little complicated one with more pieces on board (White To Move):
This is one of the positions which can occur very rarely! I believe it is a composition by someone and hasn't occurred in a real game. Here all the pieces are on the board and yet White has no moves to make. All his pawns are fixed, most of his other pieces are blocked by his own pieces and only 3 pieces which has space to move are Rook on g3, Knight on d2 and King on e1 which also cant move because if it does, the King will be under check! Unfortunately its a draw, which is called as stalemate.
Excellent explanation of stalemate by Pavan, but I think there was still some confusion in the original post about checkmate too. Here is the logical way I try to think about it.
A king attacked by an enemy piece is called "in check".
It's illegal to play a move so that your king is in check (either by moving king into check, or by shifting a pinned piece out of the line).
If you have no legal moves, for whatever reason, then the game is certainly OVER. But how?
If your king is already in check, then it's CHECKMATE and you've lost.
If your king is NOT in check, then it's STALEMATE and it's a draw.