Openings › Mate in one › February 2026 › Exercise 1 of 4
Mate in one: Black to move (exercise m1-fd1319a83e)
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 February 2026.
Last move: 49.g4 (White's pawn from g3 to g4); its two squares are marked on the board.
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 queen move or a pawn move.
Hint 2: which square?
A mating move goes to g4 or g6.
Show the solution
Two moves give checkmate:
- Qxg4# (f3 to g4). After this move, the black queen on g4 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 h4 stands in the way. g5 is covered by the black queen on g4 and the black pawn on h6. g6 is covered by the black queen on g4 and the black king on h7. The king may not take the black pawn on h6: the black pawn on g7 and the black king on h7 guard h6. The black queen on g4 cannot be captured: the king may not take it, as the black pawn on f5 guards g4. The black queen on g4 stands right next to the king, so nothing can be put in between.
- 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 g4 and pawn on h4 stand in the way. g5 is covered by the black pawn on h6. 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 king on h7 guards 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: these are the only moves that give checkmate.
The position as text
- Black to move.
- Last move: 49.g4.
- White: king h5; rook b8; pawns f4, g4, h4.
- Black: king h7; queen f3; rook a5; pawns f5, g7, h6.
- Castling: no longer allowed for either side.
- FEN:
1R6/6pk/7p/r4p1K/5PPP/5q2/8/8 b - - 0 49
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 February 2026. From a game that began with the English Opening. 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.