Winning blow: pawn to c5 (c4·8)
c9-24295naming 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.
A fork made possible by the Chess960 piece placement.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1250 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.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
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 a3, rook b1 e1, bishop g1 e2, knight d1 c2, pawn g2 h2 b3 f3 a4 c4.
Black: king b7, queen e8, rook a6 d8, bishop d6 g8, knight b6 e7, pawn d4 a5 h5 f6 g6.
14 white and 13 black pieces are on the board; the puzzle position arises after move 19.
The position in numbers
White are ahead by 1 points of material (37 against 36; 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 b7.
It is White to move on move 19, with 31 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: d.
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
19. c5 Bf4+ 20. Kb2 Be5 21. Bxa6+
Why it works
- Great move! pawn to c5 keeps the pressure (+2.7).
- Spot on — king to b2 (+2.2).
- Stunning! bishop to a6 gives up material but you stand better (+2.8).
- You win a piece — the rook.
- If instead Bf4+, then Kb2 and you stay on top.
Move by move
- 19. c5 — pawn to c5
- Bf4+ — bishop to f4 with check
- 20. Kb2 — king to b2
- Be5 — bishop to e5
- 21. Bxa6+ — bishop to a6 (capture) with check
Types in this puzzle
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
Discovered attack
A piece steps aside and opens a second attack from the piece behind it.
A discovered attack works like a curtain: one piece steps off the line and unveils the long-range piece behind it. The beauty is that the moving piece can create a second threat of its own — two attacks in one move. Look for your stacked pairs: a bishop or rook behind a knight or pawn, aimed through them at something valuable. Send the front piece to the most aggressive square — a discovery without a second threat wastes half its power.
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 #365.
SP-365 · BastionScout — King shifted to c or f, with a knight committed to the corner from move one.
The king starts on c1, the rooks on b1 and e1, the queen on f1.
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.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the BastionScout family; read right to left it becomes position 312.
The engine's main line opens with f4.
Morozov Balance Index: 16 of 100 — class D — largest edge. Engine evaluation of the starting position: +39 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #365Provenance
Mined from the project's engine self-play games.
Pack 009 · SP-365
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