Winning blow: queen to a8 (a4·2)
c9-20956naming 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 1560 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 g2, queen a4, rook c1 g1, bishop b1, knight b5, pawn a2 d2 e2 f2 h4 g5 b7.
Black: king d8, queen h8, rook d7 e8, knight h2 c6, pawn d5 h5 b6 e6 f7 g7.
13 white and 12 black pieces are on the board; the puzzle position arises after move 25.
The position in numbers
White are ahead by 1 points of material (32 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 g2, the black king on d8.
It is White to move on move 25, with 54 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 6. Files fully open (no pawns of either colour): c — natural highways for the rooks and queen.
The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
25. Qa8+ Ke7 26. Qa3+ Kd8 27. Rxc6
Why it works
- Best move. queen to a8 is exactly what the engine plays (#6).
- Well found: queen to a3 (#5).
- Precise: rook to c6 is the top choice (#4).
- You win a piece — the knight.
- If instead Ke7, then Qa3+ and you stay on top.
Move by move
- 25. Qa8+ — queen to a8 with check
- Ke7 — king to e7
- 26. Qa3+ — queen to a3 with check
- Kd8 — king to d8
- 27. Rxc6 — rook to c6 (capture)
Types in this puzzle
X-ray
A long-range piece acts through an enemy piece on the same line.
An X-ray lets a long-range piece act through an enemy piece standing on the same line — its power shines straight through. The square behind looks safe or defended, and that illusion is exactly what the tactic exploits. Check your rooks, bishops and queens: is a key square or a target hiding behind an enemy piece on their line? When counting captures on a square, include the X-ray attackers — they join the fight the moment the line opens.
About this position
These pieces come from starting position #176.
SP-176 · BastionGuard — A c- or f-file king and two knights on inner files (b–g).
The king starts on f1, the rooks on d1 and g1, the queen on h1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The pawn on f2 is defended by the king alone — the classic soft spot of the standard setup.
The setup belongs to the BastionGuard family; read right to left it becomes position 783.
The engine's main line opens with g4.
Morozov Balance Index: 2 of 100 — class D — largest edge. Engine evaluation of the starting position: +53 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #176Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-176
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads