Attack on the uncastled king: bishop to c5 (b4)
c9-19411naming 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 1060 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 h2, queen d1, rook a1 f1, bishop f3 b4, knight c1 d5, pawn g2 a3 b3 h3 c4 e4.
Black: king g8, queen d8, rook h7 a8, bishop e8 f8, knight c5, pawn a4 d4 h4 e5 c6 b7 f7 g7.
14 white and 15 black pieces are on the board; the puzzle position arises after move 16.
The position in numbers
White are ahead by 1 points of material (37 against 36; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on h2, the black king on g8.
It is White to move on move 16, with 35 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 8. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: d, f.
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
16. Bxc5 Bxc5 17. Nb4 Bf8 18. bxa4
Why it works
- Brilliant! The bishop on c5 is a sacrifice that works — you stand better (+2.7).
- knight to b4 develops smoothly.
- Precise: pawn to a4 is the top choice (+2.4).
- You reach a winning position (+2.4).
- If instead Bxc5, then Nb4 and you stay on top.
Move by move
- 16. Bxc5 — bishop to c5 (capture)
- Bxc5 — bishop to c5 (capture)
- 17. Nb4 — knight to b4
- Bf8 — bishop to f8
- 18. bxa4 — pawn to a4 (capture)
Types in this puzzle
Remove the defender
Capture the guard first — then take what it protected.
Removing the defender is the straightforward plan: capture the guard first, then take what it guarded. Unlike deflection, the defender is not lured away — it is traded off or destroyed on the spot. Stare at the target you crave and ask who defends it, and whether that defender can be profitably eaten. Count the whole capture sequence, not just the first move — the trade must pay off at the end.
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 #442.
SP-442 · RampartGuard — Both knights begin on inner files while the king sits on the wing (b/g); mirror twins stay together in this family.
The king starts on g1, the rooks on a1 and h1, the queen on d1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on e1 and f1; their long diagonals reach a5 and a6 once the d- and e-pawns step aside.
One second-rank pawn starts with no defender at all: b2.
The setup belongs to the RampartGuard family; read right to left it becomes position 709.
The engine's main line opens with c4.
Morozov Balance Index: 94 of 100 — class A — most balanced. Engine evaluation of the starting position: +10 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #442Provenance
Mined from the project's engine self-play games.
Pack 006 · SP-442
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