Winning blow: queen to a7 (a4·3)
c9-25825naming 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 1430 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 g1, queen a4, rook a1 f1, bishop b3 e3, pawn a2 b2 f2 h2 c3 d5.
Black: king b8, queen f7, rook e7 f8, bishop h3, knight f6, pawn g5 d6 b7 c7 h7.
12 white and 11 black pieces are on the board; the puzzle position arises after move 23.
The position in numbers
White are ahead by 1 points of material (31 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 g1, the black king on b8.
It is White to move on move 23, with 40 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 5. Files fully open (no pawns of either colour): e — natural highways for the rooks and queen. Half-open for White: g.
White hold the bishop pair, an edge in open lines. 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
23. Qa7+ Kc8 24. Qa8+ Kd7 25. Ba4+ c6 26. Qxb7+
Why it works
- Great move! queen to a7 keeps the pressure (+7.3).
- Well found: queen to a8 (+7.3).
- Strong! bishop to a4 is the sharp choice (+7.6).
- Great move! queen to b7 keeps the pressure (+7.5).
- You win decisive material (+7.5).
- If instead Kc8, then Qa8+ and you stay on top.
Move by move
- 23. Qa7+ — queen to a7 with check
- Kc8 — king to c8
- 24. Qa8+ — queen to a8 with check
- Kd7 — king to d7
- 25. Ba4+ — bishop to a4 with check
- c6 — pawn to c6
- 26. Qxb7+ — queen to b7 (capture) with check
Types in this puzzle
Check chase
Every move is a check — the king is chased into losing ground.
In a check chase every one of your moves is a check, so the opponent never gets a free second. The king is herded across the board until it loses a piece or walks into a decisive blow. Such lines are the easiest to calculate: each check allows only a handful of replies, so try them all. Make it a habit to start calculating any sharp position with the checks — they are the most forcing moves on the board.
About this position
These pieces come from starting position #661.
SP-661 · ThroneGuard — A central king (d or e) and two knights tucked onto inner files: the family that holds the standard array, SP-518.
The king starts on e1, the rooks on a1 and f1, the queen on h1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
The bishops stand on c1 and d1; their long diagonals reach h6 and h5 once the d- and e-pawns step aside.
Every pawn on the second rank is defended from the very first move.
The setup belongs to the ThroneGuard family; read right to left it becomes position 202.
The engine's main line opens with Nc3, bringing the knight out to c3.
Morozov Balance Index: 80 of 100 — class A — most balanced. Engine evaluation of the starting position: +17 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #661Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-661
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads