Castling-960 to the rescue on b1 (c1·9)
c9-22660naming tag (square·N)Opens in the app if installed, otherwise downloads the APK.
The tactical motive
Castling 960: the strongest move is to castle — drag the king onto its rook.
Chess960 twist: use the unusual starting setup of the pieces.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1570 ShuffleRating — club-player level.
White to move — find the best continuation
How to recognize this tactic
Chess960 castling still ends with king and rook on the classical squares (g1/f1 or c1/d1), but the path can be unusual. Watch which squares the king crosses and whether castling here opens a file, drops a defender or walks into a 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.
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 a5, rook b1 f4, knight g7, pawn a2 b2 g2 h2 b3 e4.
Black: king d7, queen g6, rook b8 f8, knight h8, pawn c6 f6 a7 b7 e7 h7.
11 white and 11 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Material is level — 28 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on c1, the black king on d7.
It is White to move on move 15, with 42 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 6. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen. Half-open for White: c, f.
The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
15. O-O-O+ Kc8 16. Ne6 b6 17. Qxa7 Rb7 18. Qa8+
Why it works
- Great move! king to c1 keeps the pressure (#4).
- Well found: knight to e6 (#3).
- Precise: queen to a7 is the top choice (#2).
- Great move! queen to a8 keeps the pressure (#1).
- You win decisive material (+15.0).
- If instead Kc8, then Ne6 and you stay on top.
Move by move
- 15. O-O-O+ — king to b1 with check
- Kc8 — king to c8
- 16. Ne6 — knight to e6
- b6 — pawn to b6
- 17. Qxa7 — queen to a7 (capture)
- Rb7 — rook to b7
- 18. Qa8+ — queen to a8 with check
Types in this puzzle
Castling to safety
One move — castling — whisks the king out of mortal danger.
Castling to safety: the only escape from the attack is to castle — one move whisks the king to g1 or c1 and brings the rook into play as a bonus. In Chess960 this leap can cross half the board, which is exactly why it slips out of sight. Whenever your king is under pressure, ask first: can I still castle? The typical blunder is throwing that right away with a careless king or rook move.
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.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
About this position
These pieces come from starting position #349.
SP-349 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on c1, the rooks on b1 and f1, the queen on e1.
The king already stands on c1, so castling long moves only the rook, from b1 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 second rank carries 2 pawns with no defender at all: a2, g2.
The setup belongs to the BastionScout family; read right to left it becomes position 328.
The engine's main line opens with f4.
Morozov Balance Index: 4 of 100 — class D — largest edge. Engine evaluation of the starting position: +50 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #349Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-349
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