Winning blow: rook to g7 (g3·5)
c9-26755naming 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 1200 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.
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 g1, rook b1 g3, bishop a1, knight f4, pawn c2 f2 g2 b3 e3 h5.
Black: king h7, queen d8, rook b4 g7, bishop a8, knight e7, pawn a3 e4 d5 h6 a7 c7 d7.
11 white and 13 black pieces are on the board; the puzzle position arises after move 20.
The position in numbers
Black are ahead by 10 points of material (22 against 32; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on h7.
It is White to move on move 20, with 30 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 7. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: a, d.
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
20. Rxg7+ Kh8 21. Ng6+ Nxg6 22. Rxd7+ Kg8 23. Rxd8+
Why it works
- Great move! rook to g7 keeps the pressure (+6.7).
- Well found: knight to g6 (+6.9).
- Strong! rook to d7 is the sharp choice (+7.0).
- Great move! rook to d8 keeps the pressure (+7.0).
- You win a piece — the queen.
- If instead Kh8, then Ng6+ and you win the rook.
Move by move
- 20. Rxg7+ — rook to g7 (capture) with check
- Kh8 — king to h8
- 21. Ng6+ — knight to g6 with check
- Nxg6 — knight to g6 (capture)
- 22. Rxd7+ — rook to d7 (capture) with check
- Kg8 — king to g8
- 23. Rxd8+ — rook to d8 (capture) with check
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.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
Discovered check
The moving piece opens a check — and is free to grab anything meanwhile.
With a discovered check the moving piece unmasks a check from the piece standing behind it. While the king deals with the check, the piece that moved grabs whatever it likes, free of charge. Look for your long-range piece on a line with the enemy king, with exactly one of your own pieces in between. The rule: among all the ways to step aside, pick the one that captures or attacks the most expensive loot.
About this position
These pieces come from starting position #418.
SP-418 · 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 b1 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.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The pawn on f2 is defended by the king alone — the classic soft spot of the standard setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 727.
The engine's main line opens with c4.
Morozov Balance Index: 100 of 100 — class A — most balanced. Engine evaluation of the starting position: -2 centipawns for White (depth 47, 400 000 000 nodes).
In 50 self-play games White scored 51.0% (95% CI 37.6–64.3%).
Explore position #418Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-418
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