Mate in three puzzles
Three moves is where guessing stops working. A mate in two can be found by trying every check; a mate in three has to be built.
- 120 positions in the course
- Difficulty 615–2289
- Section: Checkmate Patterns
- 5 levels
What changes at three moves
A mate in three is a forcing sequence in which every one of the opponent's replies loses. That is the part that gets harder, not the length: at two moves there is usually one reply to check, at three there may be six, and missing one of them makes the whole line wrong.
So this is calculation training rather than pattern training. The method that works is to identify the mating picture first -- which square, which piece -- and then work out what has to be removed or forced to get there, rather than playing checks forward and hoping.
How to spot it
- Decide what the mate looks like before you calculate. Which square does the king die on, and which piece delivers it?
- Then ask what is in the way. A defender, a flight square, or a piece of yours on the wrong square -- each of those is your first move.
- Take the opponent's replies in order of most annoying first. If the hardest defence fails, the rest will.
- Every move must be forcing. The moment a line contains a move the opponent could ignore, the count is wrong.
Three mates in three
Three positions from the 120 in this skill, easiest first. The highlighted squares are the move your opponent has just played. Work it out before you open the answer.
Position 1
Black to move. Find the best move.
Show the answer
38.Rxe4 38...Rg1+ 39.Re1 39...Rxe1+ 40.Rc1 40...Rxc1#
The line ends in checkmate. Each move in the line is forcing, so the defender never gets a free move and every branch ends in the same mating picture.
The position comes from an endgame of a real game, rated 615 for difficulty. The answer reaches checkmate.
Position 2
White to move. Find the best move.
Show the answer
29...Rc2 30.Qxf7+ Rxf7 31.Rd8+ Rf8 32.Rfxf8#
The line ends in checkmate. Each move in the line is forcing, so the defender never gets a free move and every branch ends in the same mating picture.
The position comes from the middlegame of a real game, rated 1308 for difficulty. The answer reaches checkmate.
Position 3
Black to move. Find the best move.
Show the answer
33.Qxe6 33...Qxh3+ 34.Kxh3 34...Rh7+ 35.Qh6 35...Rxh6#
The line ends in checkmate. Each move in the line is forcing, so the defender never gets a free move and every branch ends in the same mating picture.
The position comes from an endgame of a real game, rated 1898 for difficulty. The answer reaches checkmate.
Why these get miscalculated
The commonest error is calculating the line you want rather than the line they will play. If you notice you have only checked one reply to your first move, you have not solved anything yet.
The second commonest is losing the position in your head. Three moves is six plies, and pieces move in ways you stop tracking. It is worth slowing down and restating the position to yourself at the end of the line before you trust it.
Questions people ask
What is a mate in three?
A position where checkmate can be forced on the third move against any defence. Every move in the sequence must be forcing, or the opponent gets time to prevent it.
How do I calculate mate in three reliably?
Work backwards from the mating picture rather than forwards from the checks. Decide which square the king is mated on and which piece delivers it, then ask what has to be removed or deflected to allow it, and check every reply to each candidate.
Are mate in three puzzles worth doing if I am under 1200?
In small doses. They are the best available calculation training, but they are slow, and at that rating the faster gains are in mate in one, hanging pieces and back rank patterns. Do a few a week rather than a few a day.
Nearby patterns
Mate in Three sits in Checkmate Patterns. The rest of that section:
- Back Rank MatesThe king behind its own pawns
- Mate in TwoTwo forcing moves to the end
- Smothered MateThe knight and the crowded king
- Named MatesAnastasia, Boden, Arabian, Legal