Mate in 1

Solution

One solution line: Bg4#.

Position analysis

What happens on the board after the solution.

The key idea

Bg4# The king on e2 is in check from bishop g4. Its own pieces occupy f1, d2. The other escape squares are covered: d1 — bishop g4, e1 — pawn f2, f2 — queen h4, d3 — pawn e4, e3 — knight d5, f3 — pawn e4. No legal capture or block removes the check. It is checkmate.

How to find checkmate

Check the king’s escape squares and every available defense.

When check becomes checkmate

Checkmate occurs when the king is in check and its side has no legal move. With no legal move and no check, the result is stalemate.

Three ways to defend

First check whether the king can move to a safe square. Then look for a legal capture of the checking piece or a block. A knight check cannot be blocked. In double check, only a king move can get out of check.

Mate against every reply

For mate in two, choose a first move, list the opponent’s replies, and find a mate after each. The first move can be quiet. A quiet move leaving the opponent with no legal reply produces stalemate.

Sources

• FIDE Laws of Chess

Check and king safety

How to identify check and test the legality of a reply.

King safety after a move

Check your own king after the move you are considering. A pawn can leave a file and expose its king to a rook check even if the king was safe before the move.

Pinned pieces

A pinned piece still attacks squares according to its movement rules. Count those attacks when testing a king move or castling.

Reading the line of check

Locate the checking piece first. If the check travels along a line, test whether it can be blocked. Then check captures and king moves.

Sources

• FIDE Laws of Chess