Chess960 tactic on c6 (c1)
c9-11587naming 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.
Mate: a forcing sequence that ends the game — the king has no escape.
Mate in 4: a forced checkmate in four moves — every reply is covered.
Difficulty 2250 ShuffleRating — expert level — few solve it at first try.
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 is a forced mating attack. Start from the enemy king: which of its squares are already covered, and which move takes away the rest while keeping the king in check? Forcing moves — checks and captures — are what turn an attack into mate.
A mate in four is a longer forced net: each of your moves is a check or an irresistible threat, and the king is driven step by step to a square where it is finally trapped. Verify that the defender has exactly one reply at every branch.
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 c1 h5, bishop f3 d6, pawn a2 g2 d3 b4 g4.
Black: king c8, knight c7, pawn e3 b5 a6 c6 f6.
10 white and 7 black pieces are on the board; the puzzle position arises after move 37.
The position in numbers
White are ahead by 13 points of material (21 against 8; 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 c8.
It is White to move on move 37, with 44 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 5. Files fully open (no pawns of either colour): h — natural highways for the rooks and queen. Half-open for White: c, e, f.
White hold the bishop pair, an edge in open lines. 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
37. Rxc6 Kd7 38. Rh7+ Ke8 39. Rcxc7 e2 40. Rh8#
Why it works
- Best move. rook to c6 is exactly what the engine plays (#3).
- Spot on — rook to h7 (#2).
- Precise: rook to c7 is the top choice (#1).
- Best move. rook to h8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Kd7, then Rh7+ and you stay on top.
Move by move
- 37. Rxc6 — rook to c6 (capture)
- Kd7 — king to d7
- 38. Rh7+ — rook to h7 with check
- Ke8 — king to e8
- 39. Rcxc7 — rook to c7 (capture)
- e2 — pawn to e2
- 40. Rh8# — rook to h8 and it is checkmate
Types in this puzzle
Ladder mate
Two heavy pieces climb line by line, cutting off every retreat.
The ladder mate uses two heavy pieces climbing rung by rung: one cuts the king off along a line, the other checks on the next line, driving him toward the edge. It is the classic two-rook technique — check, the king retreats one rank, the other rook checks, until mate on the last rank. The only danger is the king creeping close enough to attack one of your rooks. If it does, simply slide that rook to the far side of the same line.
Mate in 4+
A long forced mating combination.
Mate in four or longer is a marathon of forcing moves where the grip must never loosen. The tools are the same: checks, double threats and sacrifices that deny the opponent a single free tempo. Do not juggle the whole tree at once — walk the main line all the way to mate first, then verify the side branches. If somewhere the defender finds one quiet move that holds, your very first move was wrong.
Absolute pin
A piece is pinned against its king — it cannot legally move.
An absolute pin freezes a piece on the line between its own king and your long-range attacker: moving it is simply illegal. The pattern is three units on one straight line — your bishop, rook or queen, an enemy piece, and the enemy king behind it. A pinned piece neither attacks nor defends anything: treat it as if it were off the board. Pile up on it, ideally with a pawn, because running away is against the rules.
About this position
These pieces come from starting position #73.
SP-73 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on f1, the rooks on c1 and h1, the queen on g1.
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.
The bishops stand on d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, b2.
The setup belongs to the BastionScout family; read right to left it becomes position 889.
The engine's main line opens with b4.
Morozov Balance Index: 34 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +31 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #73Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-73
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