♟ Chess Opening Scores

Openings › Mate in one › April 2026 › Exercise 3 of 4

Mate in one: Black to move (exercise m1-3c7a5da803)

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: 17.Ne3 (White's knight from c2 to e3); 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 knight move.

Hint 2: which square?

The mating move goes to d3.

Show the solution

One move gives checkmate:

  1. Nd3# (e5 to d3). After this move, the black knight on d3 gives check to the white king on e1, and White has no legal move: checkmate. The white king on e1 has no safe square to go to (d1, d2, e2, f1 and f2). Its own queen on d1, pawn on d2, rook on f1 and pawn on f2 stand in the way. e2 is covered by the black pawn on f3. No white piece can capture the black knight on d3. A knight's check cannot be blocked.

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 April 2026. From a game that began with the Petrov's Defense. 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.