Openings › Mate in one › April 2026 › Exercise 2 of 4
Mate in one: Black to move (exercise m1-b36b950c02)
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 April 2026.
Last move: 33.Nb5 (White's knight from a7 to b5); 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 or a knight move.
Hint 2: which square?
A mating move goes to b3 or a2.
Show the solution
Two moves give checkmate:
- Nxb3# (c1 to b3). After this move, the black knight on b3 gives check to the white king on a1, and White has no legal move: checkmate. The white king on a1 has no safe square to go to (a2, b1 and b2). a2 is covered by the black rook on e2. b1 is covered by the black bishop on f5. b2 is covered by the black rook on e2. No white piece can capture the black knight on b3. A knight's check cannot be blocked.
- Ra2# (e2 to a2). After this move, the black rook on a2 gives check to the white king on a1, and White has no legal move: checkmate. The white king on a1 has no safe square to go to (a2, b1 and b2). b1 is covered by the black bishop on f5. b2 is covered by the black rook on a2. The black rook on a2 cannot be captured: the king may not take it, as the black knight on c1 guards a2. The black rook on a2 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: 33.Nb5.
- White: king a1; bishop d4; knight b5; pawns a3, b3, c3, h4.
- Black: king f7; rook e2; bishop f5; knight c1; pawns b7, c7, f6, g7, h7.
- Castling: no longer allowed for either side.
- FEN:
8/1pp2kpp/5p2/1N3b2/3B3P/PPP5/4r3/K1n5 b - - 6 33
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 April 2026. 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.