Castling-960 to the rescue on g1 (b1)
c9-09066naming 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 1760 ShuffleRating — for advanced tacticians.
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 b1, queen e4, rook g1, bishop h1, knight b5, pawn b2 f2 h2 b3 g3 d5.
Black: king b8, queen f6, rook g8, bishop h8, knight g6, pawn g5 b6 e6 b7 f7 h7.
11 white and 11 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
Material is level — 26 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on b1, the black king on b8.
It is White to move on move 17, with 44 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): a, c — natural highways for the rooks and queen. Half-open for White: e.
The White king has 5 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
17. O-O Nf4 18. Bg2 Nxg2 19. Qa4 Nh4 20. Qa7+
Why it works
- Great move! king to g1 keeps the pressure (+4.9).
- bishop to g2 develops smoothly.
- Strong! queen to a4 is the sharp choice (+7.7).
- Best move. queen to a7 is exactly what the engine plays (#12).
- You win decisive material (+15.0).
- If instead Nf4, then Bg2 and you stay on top.
Move by move
- 17. O-O — king to g1
- Nf4 — knight to f4
- 18. Bg2 — bishop to g2
- Nxg2 — knight to g2 (capture)
- 19. Qa4 — queen to a4
- Nh4 — knight to h4
- 20. Qa7+ — queen to a7 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.
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.
960 castling G-side
Chess960 castling to the G-side — king and rook leap to g1 and f1 from unusual squares.
Castling in Chess960 looks unusual: wherever the king and rook start, G-side castling lands them on the classical destination squares — king to g1, rook to f1. Sometimes the king travels half the board; sometimes it "castles in place." The conditions are the familiar ones: neither piece has moved, the path is clear, and the king never crosses an attacked square. In the app the gesture is simple — drag your king onto the rook.
About this position
These pieces come from starting position #731.
SP-731 · RampartGuard — A wing king (b/g) with no knight on the a- or h-file.
The king starts on b1, the rooks on a1 and g1, the queen on d1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
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 RampartGuard family; read right to left it becomes position 417.
The engine's main line opens with a4.
Morozov Balance Index: 34 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +31 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #731Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-731
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads