Attack on the uncastled king: bishop to g6 (d3·4)
c9-12033naming 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 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.
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 g1, queen b1, rook g3 h3, bishop d3, knight d1 a3, pawn a2 g2 b3 c3 d4 h4.
Black: king g8, queen f4, rook e8 h8, bishop d7 f8, knight a6, pawn b5 h5 c6 g6 a7 e7 f7.
13 white and 14 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Black are ahead by 1 points of material (34 against 35; 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 g8.
It is White to move on move 15, with 30 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: e, f.
Black 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
15. Bxg6 Bg4 16. Rf3 Bxf3 17. Rxf3 Qxf3 18. gxf3
Why it works
- Great move! bishop to g6 keeps the pressure (+3.4).
- rook to f3 develops smoothly.
- Strong! rook to f3 is the sharp choice (+3.7).
- Great move! pawn to f3 keeps the pressure (+3.8).
- You win a piece — the queen.
- If instead Bg4, then Rf3 and you stay on top.
Move by move
- 15. Bxg6 — bishop to g6 (capture)
- Bg4 — bishop to g4
- 16. Rf3 — rook to f3
- Bxf3 — bishop to f3 (capture)
- 17. Rxf3 — rook to f3 (capture)
- Qxf3 — queen to f3 (capture)
- 18. gxf3 — pawn to f3 (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.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
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 #6.
SP-6 · RampartGuard — King on the wing (b/g) with both knights on inner files.
The king starts on g1, the rooks on e1 and h1, the queen on a1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on c1 and f1; their long diagonals reach h6 and a6 once the d- and e-pawns step aside.
One second-rank pawn starts with no defender at all: c2.
The setup belongs to the RampartGuard family; read right to left it becomes position 950.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 51 of 100 — class B — balanced. Engine evaluation of the starting position: +26 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #6Provenance
Mined from the project's engine self-play games.
Pack 010 · SP-6
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads