King and Queen vs. King and Pawn
In some endgames, one player has a queen and one has a pawn. Easy win, right? But, if the pawn's about to promote, things can get more complicated.
The Magic Square
The player with the queen will almost always win against (there are two exceptions that lead to draws), but she can't win by herself. To win against the pawn, the king and queen have to work together.
But, the pawn might move if the king comes closer, so what can we do?
The queen needs to get to the "magic square".
This is the square right behind the pawn.
Why is this important?
Well, let's find out.
To get the queen closer, make sure every move is a check.
If the king is in front of the pawn, the next queen move doesn't have to be a check.
Before moving the queen to the magic square, make sure that:
The enemy king is in front of the pawn (here, it's e1).
The enemy king is diagonal to the magic square (here, it's c1 or g1).
This makes sure the pawn can't move after the queen.
When the queen is on the magic square, she can put the enemy king in check while attacking the pawn.
If your opponent doesn't want to lose the pawn, they have to move the king in front of it. When they do, our king can get closer! And that's the secret to winning!
The Center Pawn
If the player with the pawn has a center pawn (d- or e-pawn), the queen can win!
Whichever way the king moves, slide your queen over in the same direction.
If the king moves away from the pawn, the queen can capture it, so the king has to move back.
Now that the enemy king is blocking the pawn, your king can get closer!
The king only had one legal move in that position.
But wait!
Do you notice something?
The pawn is pinned to the enemy king!
It can't move, so your king can get closer!
If the enemy king moves away from the pawn, you can follow the King and Queen checkmate after capturing the pawn.
If black tries to keep the pawn, you can capture and that's checkmate!
The Knight Pawn
If the player with the pawn has a knight pawn (b- or g-pawn), the queen can win! It's a bit more complicated since the king is close to the corner, but it's still possible!
Whichever way the king goes, slide your queen over to give check.
When the enemy king blocks the pawn, move your king closer.
But what if the king moves next to the pawn?
We can simply move our queen down a square!
What does this do?
It pins the pawn to the king!
Now the enemy king has to move again!
When the king goes into the corner, force him out by giving a check along the file.
When the enemy king blocks the pawn, move your king closer again.
Now checkmate is unstoppable!
The king only has one move, and Qf2 is checkmate!
The Rook Pawn
If the player with the pawn has a rook pawn (a- or h-pawn), the queen can't win! The game ends up being a draw!
The king only had one move.
Next, we give a check to force the king to block the pawn.
Then, we can get our king closer?
Or can we?
Look at the position again.
It's stalemate!
However, this only happens when the king is too far away. When the king is close enough, we can use a different technique to win!
If the queen can't get to the magic square in one move, there's another way to win.
First, we can begin setting up the checkmate by bringing the queen to the same rank as the pawn.
This is the 2nd rank for a black pawn and the 7th for a white pawn.
Our opponent only has one legal move.
Then, move your king closer.
But wait, we didn't stop our opponent's pawn!
Our opponent's pawn promoted! And it's check!
But that's okay, because this is a very special position.
We can move our king right across from our opponent's.
Look, our opponent can't stop checkmate!
Pretty cool, isn't it?
If our opponent moves the king, Qf2 is checkmate!
If our opponent moves the queen up, we can play Qf2 and then Qg2#!
If our opponent moves the queen diagonally, we can play Qf2 and then Qh2#!
The only way our opponent can delay checkmate is to give up the queen, and we still win!
But remember, this only happens if our king can reach a knight's distance away from the enemy king in one move.
The Bishop Pawn
If the player with the pawn has a bishop pawn (c- or f-pawn), the queen still can't win! The game ends up being a draw again!
Whichever way our opponent moves, we slide our queen over the same direction.
But our opponent can be sneaky and move the king into the corner.
What happens if we capture the pawn?
It's stalemate!
