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Openings › Mate in one › October 2025 › Exercise 3 of 4

Mate in one: Black to move (exercise m1-c639b6bcb2)

Black to move and mate in one. In this position Black can give checkmate with one move. The position comes from a rated Lichess game of October 2025.

Last move: 58.Kh5 (White's king from g4 to h5); its two squares are marked on the board.

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Pick a piece, then its square. Keyboard: Tab to the board, arrow keys to move, Enter or Space to pick.

Hint 1: which piece?

Look for a pawn move.

Hint 2: which square?

The mating move goes to g6.

Show the solution

One move gives checkmate:

  1. g6# (g7 to g6). After this move, the black pawn on g6 gives check to the white king on h5, and White has no legal move: checkmate. The white king on h5 has no safe square to go to (g4, g5, g6, h4 and h6). Its own pawn on g5 and pawn on h4 stand in the way. g4 is covered by the black rook on b4. The king may not take the black pawn on h6: the black king on h7 guards h6. The black pawn on g6 cannot be captured: the king may not take it, as the black knight on e7 and the black king on h7 guard g6. The black pawn on g6 stands right next to the king, so nothing can be put in between.

Our code tried every legal move of Black in this position: this is the only move that gives checkmate.

The position as text

Where this exercise comes from

The position comes from a rated game in our sample of the Lichess open database (CC0 1.0), from the monthly file of October 2025. From a game that began with the London System. In that game Black gave checkmate with the next move. We show no player names and no link to the game. Our code tried every legal move of the position and lists every move that gives checkmate; the list, the hints and the explanations are checked again each time the site is built. How the exercises are chosen: Mate in one and How it works.