Attack on the uncastled king: knight to d7 (e5·17)
c9-23228naming 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.
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 1200 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.
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, rook a1 f1, bishop c1 b3, knight g3 e5, pawn a2 b2 g2 h2 d4 f4.
Black: king f8, queen b8, rook a8 g8, bishop d7 d8, knight b1 h8, pawn c6 e6 a7 b7 f7 g7 h7.
13 white and 15 black pieces are on the board; the puzzle position arises after move 11.
The position in numbers
Black are ahead by 10 points of material (28 against 38; 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 f8.
It is White to move on move 11, with 34 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: c, e.
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
11. Nxd7+ Ke7 12. Nxb8 Rxb8 13. Be3 f5 14. Rfxb1
Why it works
- Great move! knight to d7 keeps the pressure (+5.1).
- Well found: knight to b8 (+5.1).
- A natural move: bishop to e3.
- Best move. rook to b1 is exactly what the engine plays (+5.1).
- You win a piece — the queen.
- If instead Ke7, then Nxb8 and you win the queen.
Move by move
- 11. Nxd7+ — knight to d7 (capture) with check
- Ke7 — king to e7
- 12. Nxb8 — knight to b8 (capture)
- Rxb8 — rook to b8 (capture)
- 13. Be3 — bishop to e3
- f5 — pawn to f5
- 14. Rfxb1 — rook to b1 (capture)
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.
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.
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.
About this position
These pieces come from starting position #597.
SP-597 · BastionScout — Off-centre king plus a rim knight (a/h): 168 positions carry this shape.
The king starts on f1, the rooks on a1 and g1, the queen on b1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
The bishops stand on c1 and d1; their long diagonals reach h6 and h5 once the d- and e-pawns step aside.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the BastionScout family; read right to left it becomes position 266.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 91 of 100 — class A — most balanced. Engine evaluation of the starting position: +13 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #597Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-597
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