Trap the knight on b1
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The tactical motive
Trapped piece: an enemy piece has no safe squares — catch it.
Difficulty 1526 ShuffleRating — club-player level.
White to move — find the best continuation
How to recognize this tactic
A trapped piece has no safe square. Spot an enemy piece that has wandered offside or been hemmed in, then play the move that takes away its last escape and wins it — often a quiet pawn push or a covering minor piece.
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 h1, queen d1, rook a1 f1, bishop h2, knight d2 a4, pawn a2 g2 c3 h3 c4 e4.
Black: king g8, queen a3, rook d8 f8, bishop e7, knight e6 f6, pawn c6 d6 a7 b7 f7 g7 h7.
13 white and 14 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
Black are ahead by 1 points of material (34 against 35; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on h1, the black king on g8.
It is White to move on move 17, with 35 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: b, d, f.
The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
17. Nb1 Qxa4 18. Qxa4
Why it works
- Great move! knight to b1 keeps the pressure (+3.6).
- Well found: queen to a4 (+3.8).
- You win a piece — the queen.
- If instead Qxa4, then Qxa4 and you win the queen.
Move by move
- 17. Nb1 — knight to b1
- Qxa4 — queen to a4 (capture)
- 18. Qxa4 — queen to a4 (capture)
Types in this puzzle
Quiet move
No check, no capture — yet this modest move decides the game.
A quiet move gives no check and takes nothing — yet it decides the game by creating an unstoppable threat or stealing the king's last square. This is the hardest class of moves: the eye hunts for loud blows while a modest shift does the winning. The clue: every forcing try runs into a defense, so seek the move that strengthens the threat or takes squares away. Train yourself to ask: what if I neither capture nor check, but quietly improve?
Provenance
Derived from the Lichess puzzle database (CC0).
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 011
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