Winning blow: rook to d3 (c3·3)
c9-08811naming 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.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1470 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.
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 a1, rook d1 c3, bishop h1, knight d5, pawn h2 b3 e3 a4.
Black: king d8, queen e2, rook d6 b8, bishop g4, pawn b4 a5 c7 h7.
10 white and 9 black pieces are on the board; the puzzle position arises after move 23.
The position in numbers
White are ahead by 3 points of material (29 against 26; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on d8.
It is White to move on move 23, with 29 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 4 pawns, Black 4. Files fully open (no pawns of either colour): d, f, g — natural highways for the rooks and queen. Half-open for White: c.
The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
23. Rcd3 Rc6+ 24. Nc3+ Ke7 25. Bxc6
Why it works
- Great move! rook to d3 keeps the pressure (+6.5).
- Well found: knight to c3 (+7.7).
- Strong! bishop to c6 is the sharp choice (+9.0).
- You win a piece — the rook.
- If instead Kc8, then Qh8+ and you stay on top.
Move by move
- 23. Rcd3 — rook to d3
Types in this puzzle
Quiet move
No check, no capture — yet this modest move decides the game.
A quiet move gives no check and takes nothing — yet it decides the game by creating an unstoppable threat or stealing the king's last square. This is the hardest class of moves: the eye hunts for loud blows while a modest shift does the winning. The clue: every forcing try runs into a defense, so seek the move that strengthens the threat or takes squares away. Train yourself to ask: what if I neither capture nor check, but quietly improve?
About this position
These pieces come from starting position #879.
SP-879 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
The king starts on c1, the rooks on b1 and d1, the queen on a1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: e2.
The setup belongs to the BastionGuard family; read right to left it becomes position 80.
The engine's main line opens with b4.
Morozov Balance Index: 1 of 100 — class D — largest edge. Engine evaluation of the starting position: +66 centipawns for White (depth 43, 400 000 000 nodes).
In 50 self-play games White scored 60.0% (95% CI 46.2–72.4%).
Explore position #879Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-879
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