Mate in 2: discovered attack on a5
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The tactical motive
Discovered attack: one piece steps aside, unleashing another's attack.
Mate in 2: the first move creates an unstoppable threat, the second delivers mate.
Difficulty 1441 ShuffleRating — club-player level.
White to move — find the best continuation
How to recognize this tactic
A discovered attack fires when one piece steps aside and unmasks the piece behind it. Look for your own units that block a rook, bishop or queen: moving the front piece — ideally with a threat of its own — springs two attacks in one move.
Mate in two usually opens with a forcing move — a check, a capture or an unstoppable threat — that strips the king of squares or defenders, so the follow-up mate becomes unavoidable. Look for the first move that leaves the opponent only losing replies.
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 d2, rook d1 h1, bishop g4, pawn f2 g2 h2.
Black: king a7, queen b3, rook d8 h8, bishop f8, knight g8, pawn b7 c7 f7 g7 h7.
8 white and 11 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
Black are ahead by 5 points of material (25 against 30; 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 a7.
It is White to move on move 17, with 37 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 5. Files fully open (no pawns of either colour): a, d, e — natural highways for the rooks and queen. Half-open for White: b, c.
The White king has 0 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
17. Qa5+ Kb8 18. Rxd8#
Why it works
- Great move! queen to a5 keeps the pressure (#1).
- Well found: rook to d8 (#).
- The line ends in a forced mate in 2.
- If instead Kb8, then Rxd8# and it is mate.
Move by move
- 17. Qa5+ — queen to a5 with check
- Kb8 — king to b8
- 18. Rxd8# — rook to d8 (capture) and it is checkmate
Types in this puzzle
Mate in 2
A forced checkmate in two moves.
Mate in two: your move, any reply, then the mating blow. Start with the most forcing first moves — checks and sacrifices that shrink the opponent's options to almost nothing. Against every single reply you must have a mate ready, so check them all without exception. The common failure is analyzing the pretty defense and forgetting the boring one.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
Provenance
Derived from the Lichess puzzle database (CC0).
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 011
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