How to Checkmate a Knight King in Gangster King
· Gangster King
To checkmate a knight king, give check with a piece the king cannot capture, and make sure every square it could jump to is attacked or blocked. A knight king cannot be shut in by a wall of pieces, because it leaps over them. The only way to trap it is to take away its landing squares one by one, and that is easiest when the king is on the edge or in a corner.
This guide uses the knight as the king of the day. If you have not read the rules yet, start with how to play Gangster King. You can try everything below in a free game on the Gangster King page.
How a knight king moves
A knight king makes only knight jumps. It can reach up to eight squares in the middle of the board, but fewer near the edge. Jumping means that pieces standing between the start and the landing square never matter. A landing square is unavailable in only two cases: one of your own pieces stands on it, or an enemy piece attacks it.
In the middle of the board the knight king has eight squares to jump to, so it is very hard to mate there. From e4 this king can go to c3, c5, d2, d6, f2, f6, g3, g5.
In the corner the knight king on h8 has only two squares: g6 and f7. A corner is where it is weakest. From h8 this king can go to f7, g6.
Two things follow. First, the usual defences against check change. A check from a rook, bishop or queen can still be blocked, but a king that is not checked simply jumps away, so you rarely need to block. Second, a king cannot be trapped by closing the squares next to it. What matters are the squares a knight's jump away.
Why one check is not enough
Imagine the enemy knight king is on h8 and you put a rook on the h-file. In ordinary chess this would be a strong attack. Here the king has two escapes, g6 and f7, and the rook controls neither.
The rook gives check on the h-file, but Black simply jumps to g6 or f7. Those are the only two legal moves, and both are safe.
The same is true for a queen on the back rank. A check on its own does nothing: you need to cover both jump squares at the same moment.
The queen checks along the eighth rank. Black still has g6 and f7 to jump to, so this is not mate.
Two checkmates in the corner
To mate, combine a checking piece with a second piece that covers the landing squares. Here is a rook and queen team. The rook on g8 gives check and also controls the g-file, so g6 is covered. The queen on a7 sweeps the seventh rank, so f7 is covered. The rook cannot be captured, because g8 is not a knight's jump from h8.
Checkmate. The rook on g8 gives check and covers g6; the queen on a7 covers f7. The knight king has no safe jump.
A knight can do the covering job as well. A knight on e5 attacks both g6 and f7, the two landing squares at once. Add a queen checking along the rank and the mate is complete.
Checkmate. The queen on a8 gives check; the knight on e5 attacks both g6 and f7.
This is the pattern to look for: one piece gives the check, another covers the two jump squares. A knight on e5 does both covering jobs alone, which is why knights are so useful against a knight king in the corner.
Do not forget the king can capture
A king that cannot escape by moving to an empty square can still jump onto one of your pieces, if the piece is not protected. A queen placed on g6 looks scary, but it can be taken.
The queen covers f7, but it is not protected, so Black's only legal move is h8xg6. Always check that the piece next to the king is defended.
Black has exactly one legal move here, and it wins the queen. When you attack a landing square by standing on it, make sure that something protects your piece.
Watch out for stalemate
A knight king in the corner has so few moves that it is easy to take them all away without giving check. The position below looks like a successful attack. The queen on g6 is now protected by the rook on g1, so the king cannot capture it, and the queen also covers f7. But the king is not in check.
Stalemate. Black is not in check and has no legal move, so the game is a draw even though White has an overwhelming advantage.
Before you make a move that takes the last square away, ask whether your move also gives check. If it does not, leave the king one square, or find a move that does.
A smothered mate against your own pieces
Your own pieces can finish the job for the attacker. A knight king that has its own pawns on both jump squares has nowhere to go, and a single check along the file is enough.
Checkmate. The queen on h1 checks along the h-file. Black's own pawns stand on g6 and f7, the king's only two jumps.
So if your king sits in the corner, do not leave both of the jump squares filled with your own pieces. In this variant it is a good habit to keep your king where it has several different squares to jump to, and to check which of them your opponent can attack.
A plan to mate a knight king
- Drive the king to the edge. In the centre it has up to eight squares, on the edge four or fewer, in the corner two. Take away squares with your pieces and the king will have to retreat towards the edge.
- Bring a knight close. Knights attack the very squares the king jumps to, so they are the best helpers. A knight king standing a jump from your knight cannot go there.
- Find the check last. Cover the landing squares first with quiet moves, and give the check at the end. A check that comes too early just lets the king leave.
- Protect every piece you use to cover a square. An unprotected piece one jump from the king can be captured.
- Count the squares before each move. After the move, list the king's remaining jumps. If there are none and you are not giving check, it is stalemate.
Practise it
The knight comes up as the king of the day once in every seven days. The Gangster King page shows today's piece, and against the computer you can choose the knight king to practise these mates whatever the day. For the general skills behind it, read how to develop your pieces, which works in every game, including this one.