Winning blow: rook to f8 (f1)
c9-14614naming 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.
A fork made possible by the Chess960 piece placement.
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.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
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 d1, queen g2, rook b1 f1, knight h3 g4, pawn a2 c2 d2 e2 h2 b3.
Black: king c7, queen f8, rook a8 e8, bishop a1, knight d6 g8, pawn e4 g5 b6 c6 a7 d7.
12 white and 13 black pieces are on the board; the puzzle position arises after move 14.
The position in numbers
Black are ahead by 3 points of material (31 against 34; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d1, the black king on c7.
It is White to move on move 14, with 39 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): f — natural highways for the rooks and queen. Half-open for White: g.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
14. Rxf8 Rxf8 15. Rxa1
Why it works
- Great move! rook to f8 keeps the pressure (+4.1).
- Spot on — rook to a1 (+4.1).
- You win a piece — the queen.
- If instead Rxf8, then Rxa1 and you win the queen.
Move by move
- 14. Rxf8 — rook to f8 (capture)
- Rxf8 — rook to f8 (capture)
- 15. Rxa1 — rook to a1 (capture)
Types in this puzzle
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
X-ray
A long-range piece acts through an enemy piece on the same line.
An X-ray lets a long-range piece act through an enemy piece standing on the same line — its power shines straight through. The square behind looks safe or defended, and that illusion is exactly what the tactic exploits. Check your rooks, bishops and queens: is a key square or a target hiding behind an enemy piece on their line? When counting captures on a square, include the X-ray attackers — they join the fight the moment the line opens.
About this position
These pieces come from starting position #643.
SP-643 · ThroneGuard — A central king (d or e) and two knights tucked onto inner files: the family that holds the standard array, SP-518.
The king starts on d1, the rooks on b1 and e1, the queen on f1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 211.
The engine's main line opens with g4.
Morozov Balance Index: 89 of 100 — class A — most balanced. Engine evaluation of the starting position: +14 centipawns for White (depth 43, 400 000 000 nodes).
Explore position #643Provenance
Mined from the project's engine self-play games.
Pack 004 · SP-643
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