Mate in 3: discovered attack on b3
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The tactical motive
Discovered attack: one piece steps aside, unleashing another's attack.
Mate in 3: a forced sequence that ends in checkmate.
Difficulty 1953 ShuffleRating — for advanced tacticians.
Black 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.
In a mate in three every move must be forcing; the defender should never get a free tempo. Find the check or threat that herds the king, calculate the single defence to each, and confirm the net closes on the third move.
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 b1, queen h2, rook d1 h1, bishop d2, knight b3, pawn a2 c2 f3 e4 g4.
Black: king g8, queen c8, rook c3 f8, bishop e6, knight b4, pawn a6 d6 g6 b7 e7.
11 white and 11 black pieces are on the board; the puzzle position arises after move 23.
The position in numbers
Material is level — 30 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on b1, the black king on g8.
It is Black to move on move 23, with 44 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 5. Files fully open (no pawns of either colour): h — natural highways for the rooks and queen. Half-open for Black: c, f.
The Black king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
23... Rxb3+ 24. axb3 Qxc2+ 25. Ka1 Qa2#
Why it works
- Great move! rook to b3 keeps the pressure (#2).
- Well found: queen to c2 (#1).
- Strong! queen to a2 is the sharp choice (#).
- The line ends in a forced mate in 3.
- If instead axb3, then Qxc2+ and you stay on top.
Move by move
- 23… Rxb3+ — rook to b3 (capture) with check
- 24. axb3 — pawn to b3 (capture)
- Qxc2+ — queen to c2 (capture) with check
- 25. Ka1 — king to a1
- Qa2# — queen to a2 and it is checkmate
Types in this puzzle
Supported queen mate
The queen delivers mate face to face, protected by a friend.
The supported queen mate is the most common pattern of all: the queen lands next to the king and mates because a friendly piece or pawn protects her. The king is helpless — capturing is impossible, and the queen covers every neighboring square herself. Hunt for a protected square beside the enemy king: a knight, bishop or pawn eyeing it turns her invasion into mate. Verify one thing — that the square really is defended, or the king eats her.
Mate in 3
A forced checkmate in three moves.
Mate in three is a forced staircase: each of your moves narrows the opponent's choices, and the third one ends the game. Look for the start among checks and sacrifices — quiet first moves are rare in mating problems, but deliciously sneaky. Keep the tree in your head: every defense gets its own branch. Do not stop calculating after move two — see the final mating picture with your own eyes.
Mate defense
Mate is threatened — parry it and stay on top.
Mate defense: your opponent is one move from mating you — but it is your turn, and that changes everything. Find the defense that kills the mating threat while keeping your advantage: often a check or a counter-threat that leaves no time for the mate. First name the exact square where the mate would land — otherwise you are defending blind. The mistake is playing a "defensive" move that does not actually remove the threat.
Provenance
Derived from the Lichess puzzle database (CC0).
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 014
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