Attack on the uncastled king: bishop to f6 (g5·6)
c9-28175naming 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.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1700 ShuffleRating — for advanced tacticians.
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.
An uncastled king in the centre is a standing target. Look for ways to open the central files and diagonals against it with checks and threats before it can shelter — every tempo the king spends in the middle is a chance for a combination.
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 b2, rook a1 h1, bishop e2 g5, pawn g2 h2 d3 e4 d6.
Black: king d8, queen a4, rook c2 h8, bishop f7, knight f6 a8, pawn b4 b5 a7 d7 g7 h7.
11 white and 13 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
Black are ahead by 4 points of material (30 against 34; 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 d8.
It is White to move on move 18, with 38 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 6. Files fully open (no pawns of either colour): c, f — natural highways for the rooks and queen. Half-open for White: a, b.
White hold the bishop pair, an edge in open lines. 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
18. Bxf6+ Kc8 19. Qxc2+ Qxc2+ 20. Kxc2 gxf6 21. Rxa7
Why it works
- Great move! bishop to f6 keeps the pressure (+4.6).
- Well found: queen to c2 (+4.6).
- Strong! king to c2 is the sharp choice (+4.8).
- Best move. rook to a7 is exactly what the engine plays (+4.7).
- You win a piece — the queen.
- If instead Kc8, then Qxc2+ and you win the rook.
Move by move
- 18. Bxf6+ — bishop to f6 (capture) with check
- Kc8 — king to c8
- 19. Qxc2+ — queen to c2 (capture) with check
- Qxc2+ — queen to c2 (capture) with check
- 20. Kxc2 — king to c2 (capture)
- gxf6 — pawn to f6 (capture)
- 21. Rxa7 — rook to a7 (capture)
Types in this puzzle
Win the pinned piece
The pinned piece cannot run — attack it again and win it.
A pinned piece cannot flee, which means you can win it outright by attacking it one more time. Count attackers against defenders: if you outnumber them, the piece is yours. The best extra attacker is a pawn, since it costs less than anything it might capture. Do not rush the capture — build up the pressure first, then harvest.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
Uncastled king
The king lingered in the middle — punish the delay.
Punishing the uncastled king: your opponent delayed castling, and now his king is stuck on its starting square under fire. In Chess960 this is deadlier than in classical chess — the king may start in the center or near the edge, and the familiar defensive setups simply do not apply. The signs: the victim still holds castling rights, and the files toward his king are half-open. Open lines before the king manages to hide.
About this position
These pieces come from starting position #238.
SP-238 · ThroneScout — A knight starts on the edge (a/h) and the king sits centrally on d or e; the mirror twin stays in this family too.
The king starts on d1, the rooks on b1 and h1, the queen on c1.
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 f1 and g1; their long diagonals reach a6 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 ThroneScout family; read right to left it becomes position 628.
The engine's main line opens with c4.
Morozov Balance Index: 4 of 100 — class D — largest edge. Engine evaluation of the starting position: +50 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #238Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-238
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