Openings › Mate in one › September 2026 › Exercise 1 of 5
Mate in one: Black to move (exercise m1-2e9854753d)
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 September 2026.
Last move: 48.Ba1 (White's bishop from c3 to a1); 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 rook move.
Hint 2: which square?
The mating move goes to h3.
Show the solution
One move gives checkmate:
- Rh3# (a3 to h3). After this move, the black rook on h3 gives check to the white king on h1, and White has no legal move: checkmate. The white king on h1 has no safe square to go to (g1, g2 and h2). g1 is covered by the black rook on g4. g2 is covered by the black rook on g4. h2 is covered by the black rook on h3. No white piece can capture the black rook on h3. No white piece can move to h2 to block the check.
Our code tried every legal move of Black in this position: this is the only move that gives checkmate.
The position as text
- Black to move.
- Last move: 48.Ba1.
- White: king h1; rook b1; bishop a1; pawns d4, e5.
- Black: king g8; rooks a3, g4; pawns a4, d5, e6, f7, g7.
- Castling: no longer allowed for either side.
- FEN:
6k1/5pp1/4p3/3pP3/p2P2r1/r7/8/BR5K b - - 5 48
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 September 2026. From a game that began with the Queen's Gambit Declined. 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.