This position is often the result of a game well-played: your advantage is overwhelming and this is a "won position", nevertheless, you still actually have to win this game.
This post deals with the Queen checkmate and guides you through the whole process. All screenshots are taken from Chess Trainer.
Now the question is: how do we manage to get to the above position starting from a random one. Here is how:
Let's first play a few moves
We do not know yet on which side we are going to trap the black King. A good move is therefore to centralize the white King. Here, Black has no other choice than moving to c5.
It is probably best to keep moving the King, as we will need it anyway. Again, Black can only play the King to c6
At this point, it is hard to progress with the white King, because it is blocked by the black King. So the best option is to reduce Black's vital space with the Queen.
Now the black King is trapped in the box. The goal of the next moves is to make the box smaller
Let's continue a few moves
The way has been clear for the white King. The black King has no other choice than going to the side of the board.
Here almost everything is winning, but Kc7 is a quick way to kill the game. Black's answer is forced.
4. Qc6 Stalemate
Oooops ! This is what happens when you play carelessly. Be very careful shen the opposing King is on the edge of the chessboard. A draw by stalemate is always possible.
Now let's play the correct move !
This is checkmate !
To sum up, checkmating with one Queen against a sole King requires the following plan:
- Try to bring your King to the center. If you are blocked by the enemy King, use your Queen to clear the way
- When your King is in the center, push the other King to one side of the board, switching between Queen moves (to trap the enemy King in ever smaller rectangles) and King moves (to get it closer for the final mate)
- Once the enemy King is trapped to the side, avoid any possible stalemate !
- Then bring your King close and, on the last move, deliver checkmate with your Queen, protected by the King
This checkmate is the most common one, be sure to know it, because you should never let your opponent escape when he is one queen down !