Attack on the uncastled king: knight to c4 (d2·7)
c9-13539naming 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 920 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 d3, rook b1 e2, bishop h1, knight d2, pawn c2 f2 g3 a4 b5.
Black: king c8, rook e4 b8, bishop d4, pawn c4 f5 b6 d6 d7 h7.
10 white and 10 black pieces are on the board; the puzzle position arises after move 27.
The position in numbers
White are ahead by 2 points of material (21 against 19; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d3, the black king on c8.
It is White to move on move 27, with 2 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 5 pawns, Black 6. Files fully open (no pawns of either colour): e — natural highways for the rooks and queen. Half-open for White: d, h.
The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
27. Nxc4 Rxe2 28. Kxe2
Why it works
- Great move! knight to c4 keeps the pressure (+5.5).
- Spot on — king to e2 (+5.3).
- You win decisive material (+5.3).
- If instead Rxe2, then Kxe2 and you stay on top.
Move by move
- 27. Nxc4 — knight to c4 (capture)
- Rxe2 — rook to e2 (capture)
- 28. Kxe2 — king to e2 (capture)
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.
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 #879.
SP-879 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
The king starts on c1, the rooks on b1 and d1, the queen on a1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: e2.
The setup belongs to the BastionGuard family; read right to left it becomes position 80.
The engine's main line opens with b4.
Morozov Balance Index: 1 of 100 — class D — largest edge. Engine evaluation of the starting position: +66 centipawns for White (depth 43, 400 000 000 nodes).
In 50 self-play games White scored 60.0% (95% CI 46.2–72.4%).
Explore position #879Provenance
Mined from the project's engine self-play games.
Pack 004 · SP-879
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