Winning blow: rook to a4 (a1)
c9-19065naming tag (square·N)Opens in the app if installed, otherwise downloads the APK.
The tactical motive
Chess960 twist: use the unusual starting setup of the pieces.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1060 ShuffleRating — club-player level.
White to move — find the best continuation
How to recognize this tactic
In Chess960 the pieces start on unfamiliar squares, so tactics appear earlier and from unusual angles. Do not trust classical patterns — read the actual lines of the bishops, the rooks and the queen from where they really stand in this position.
This position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
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 h4, rook a1, knight e5 f5, pawn d2 e2 h2 c3 g3 b4.
Black: king b8, queen a4, rook e8, bishop g8, knight b6 e6, pawn d5 a6 g6 b7 c7 h7.
11 white and 12 black pieces are on the board; the puzzle position arises after move 27.
The position in numbers
Black are ahead by 3 points of material (26 against 29; 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 b8.
It is White to move on move 27, with 41 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 6. Files fully open (no pawns of either colour): f — natural highways for the rooks and queen. Half-open for White: a.
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
27. Rxa4 Nxa4 28. Nh6 d4 29. Nxg8
Why it works
- Great move! rook to a4 keeps the pressure (+4.6).
- Spot on — knight to h6 (+4.5).
- Precise: knight to g8 is the top choice (+4.5).
- You win a piece — the queen.
- If instead Nxa4, then Nh6 and you win the queen.
Move by move
- 27. Rxa4 — rook to a4 (capture)
- Nxa4 — knight to a4 (capture)
- 28. Nh6 — knight to h6
- d4 — pawn to d4
- 29. Nxg8 — knight to g8 (capture)
Types in this puzzle
Trapped piece
The attacked piece has no safe square — it is caught.
Trapping a piece means the attacked piece has no safe square left — it simply perishes. Do not chase it around; build a cage instead: cut off the escape squares with pawns and pieces first, and attack last. The typical victim has wandered deep into your camp or is stuck at the edge of the board, where its mobility is tiny. And always check the way home for your own raiders — or the trapped piece will be yours.
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.
About this position
These pieces come from starting position #349.
SP-349 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on c1, the rooks on b1 and f1, the queen on e1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
The bishops stand on d1 and g1; their long diagonals reach h5 and a7 once the e- and f-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, g2.
The setup belongs to the BastionScout family; read right to left it becomes position 328.
The engine's main line opens with f4.
Morozov Balance Index: 4 of 100 — class D — largest edge. Engine evaluation of the starting position: +50 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #349Provenance
Mined from the project's engine self-play games.
Pack 006 · SP-349
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