Winning blow: bishop to a5 (b6)
c9-23351naming 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 1390 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 d1, queen e3, bishop b6, knight e2 f2, pawn a2 g2 e4 f5.
Black: king c6, queen g8, rook a8, bishop e8, pawn b3 g5 a6 d6 f6 e7.
9 white and 10 black pieces are on the board; the puzzle position arises after move 20.
The position in numbers
Black are ahead by 1 points of material (22 against 23; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d1, the black king on c6.
It is White to move on move 20, with 37 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 4 pawns, Black 6. Files fully open (no pawns of either colour): c, h — natural highways for the rooks and queen. Half-open for White: b, d.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
20. Ba5 Bh5 21. Qb6+ Kd7 22. Qb7+ Ke8 23. Qxa8+
Why it works
- Great move! bishop to a5 keeps the pressure (+6.2).
- Well found: queen to b6 (+6.4).
- Strong! queen to b7 is the sharp choice (+6.3).
- Great move! queen to a8 keeps the pressure (+6.7).
- You win a piece — the rook.
- If instead Bh5, then Qb6+ and you stay on top.
Move by move
- 20. Ba5 — bishop to a5
- Bh5 — bishop to h5
- 21. Qb6+ — queen to b6 with check
- Kd7 — king to d7
- 22. Qb7+ — queen to b7 with check
- Ke8 — king to e8
- 23. Qxa8+ — queen to a8 (capture) with check
Types in this puzzle
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
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?
About this position
These pieces come from starting position #632.
SP-632 · ThroneScout — The king starts on d or e while at least one knight begins in a corner.
The king starts on d1, the rooks on a1 and g1, the queen on f1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: b2, h2.
The setup belongs to the ThroneScout family; read right to left it becomes position 237.
The engine's main line opens with c3.
Morozov Balance Index: 43 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +28 centipawns for White (depth 50, 400 000 000 nodes).
Explore position #632Provenance
Mined from the project's engine self-play games.
Pack 010 · SP-632
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