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Mate in One: Exercises From Rated Lichess Games
50 mate-in-one exercises, generated by our code from positions in rated Lichess games of our sample. In each one, the side to move can give checkmate with one move. Find the move on the board, open a hint if you like, then open the solution: it lists every move that gives checkmate and says why each one does.
Start with exercise 1 of September 2026 (Black to move). Each exercise links to the next one of its month. White is to move in 25 of them and Black in 25.
Puzzle of the day: one of these exercises each day, in a fixed order that changes at 00:00 UTC.
The monthly sets, newest first
Each set holds the exercises from games of one monthly Lichess file.
How the exercises are chosen
- Each one is the position just before a checkmate that was played in a rated game of our Lichess sample (the same stored monthly samples as the rest of this site). We leave out the terminations and the speeds our other pages leave out (UltraBullet and correspondence games are not used); the other rules our statistics use to leave out games are not applied here.
- From each stored slice of a monthly Lichess file we take at most one position, and the slices are spread over the month's file.
- The side to move has at least eight legal moves, and at most three of them give checkmate.
- The game's mate came at its 20th half-move or later, which leaves out quick opening traps.
- We leave out a bare king against nine or more points of material (pawn 1, knight 3, bishop 3, rook 5, queen 9): the end of a won ending.
- Within a slice we look at the first 8 positions that pass these rules and keep the one whose side to move, then whose mating piece, has the fewest exercises so far, so that both colours and different pieces appear.
- Each position appears once: positions are compared as the rules of chess compare them.
- Our code tries every legal move of each position and lists every move that mates; the list, the hints and the explanations are made again from the position each time the site is built.
The positions come from the Lichess open database (CC0 1.0), from the same stored monthly samples as the rest of this site. We show no player names and no links to the games. More about the data: How it works.