Attack on the uncastled king: knight to d2 (b1)
c9-05946naming 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 970 ShuffleRating — for beginners taking their first steps in Chess960 tactics.
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 c1, queen f1, rook a1 h1, bishop d1, knight b1 e1, pawn b2 c2 h2 d3 a4 g4.
Black: king c8, queen h6, rook a8, bishop f7 d8, knight d4 c6, pawn a5 e6 b7 c7 d7.
13 white and 12 black pieces are on the board; the puzzle position arises after move 13.
The position in numbers
White are ahead by 3 points of material (34 against 31; 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 c8.
It is White to move on move 13, with 3 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 6 pawns, Black 5. Files fully open (no pawns of either colour): f — natural highways for the rooks and queen. Half-open for White: e.
Black hold the bishop pair, an edge in open lines. The White king has 0 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
13. Nd2 Bg5 14. Qg2 O-O-O 15. h4
Why it works
- Great move! knight to d2 keeps the pressure (+2.4).
- queen to g2 develops smoothly.
- A natural move: pawn to h4.
- You reach a winning position (+2.5).
- If instead Bg5, then Qg2 and you stay on top.
Move by move
- 13. Nd2 — knight to d2
Types in this puzzle
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
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.
Blocking save
Block the check with tempo — and turn the game around.
The blocking save: you interpose a piece against the check — not passively, but with tempo, so the blocker creates a threat of its own. Such a block turns defense into attack. Whenever you are checked, compare all three replies — capture, move the king, interpose — and among the interpositions hunt for the one that counterattacks. The mistake is automatically stepping aside with the king when an active block would have turned the game around.
About this position
These pieces come from starting position #557.
SP-557 · BastionGuard — Off-centre king (c/f), no knight on the a- or h-file.
The king starts on c1, the rooks on a1 and h1, the queen on f1.
The king already stands on c1, so castling long moves only the rook, from a1 to d1.
The bishops stand on d1 and g1; their long diagonals reach h5 and a7 once the e- and f-pawns step aside.
The pawn on b2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the BastionGuard family; read right to left it becomes position 504.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 0 of 100 — class D — largest edge. Engine evaluation of the starting position: +63 centipawns for White (depth 44, 400 000 000 nodes).
In 50 self-play games White scored 65.0% (95% CI 51.1–76.7%).
Explore position #557Provenance
Mined from the project's engine self-play games.
Verified by Stockfish at depth 20+.
Solution forcedness confirmed (verified).
Pack 005 · SP-557
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