Mate in 1: queen to a3
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The tactical motive
Mate in 1: find the move after which the enemy king has no escape.
Difficulty 1477 ShuffleRating — club-player level.
White to move — find the best continuation
How to recognize this tactic
A mate in one hides among forcing checks. Run through every check you can give: does it cover all the king's escape squares, is the checking piece safe or supported, and can nothing block or capture it? If yes, that is the mate.
General method: before you move, list the forcing candidates — every check, every capture, every direct threat — and calculate those first. The solution to a tactic is almost always among them.
Position on the board
White: king c1, queen f3, rook d1 h1, knight g1 c7, pawn a2 b2 c2 g2 h2.
Black: king e7, queen c8, rook a8 h8, bishop e4, knight b8, pawn e6 f6 a7 b7 f7 h7.
11 white and 12 black pieces are on the board; the puzzle position arises after move 16.
The position in numbers
Black are ahead by 1 points of material (30 against 31; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on e7.
It is White to move on move 16, with 45 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 6. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen. Half-open for White: e, f.
The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
16. Qa3#
Why it works
- Great move! queen to a3 keeps the pressure (#).
- The line ends in a forced mate in 1.
Move by move
- 16. Qa3# — queen to a3 and it is checkmate
Types in this puzzle
Mate in 1
Checkmate in a single move — find it.
Mate in one: the combination is over, only the final precise shot remains. The method is simple — list every check you have and test the three escapes against each: king moves, blocks, and capturing the checker. If none of them works, it is mate. The classic blunder is falling in love with the first check you see and missing the one escape hatch.
Relative pin
A piece shields a more valuable one behind it — moving it loses material.
In a relative pin the piece shields not its king but something valuable behind it, usually the queen. Moving is legal but costly, because the piece behind falls. Look for three units on one line: your long-range piece, a cheaper enemy piece, and an expensive one hiding behind. Beware the classic trap — a relatively pinned piece can still move with check or a bigger threat, so verify before you cash in.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
Provenance
Derived from the Lichess puzzle database (CC0).
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 011
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