Attack on the uncastled king: rook to c6 (c2)
c9-15831naming 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.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 2120 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.
An uncastled king in the centre is a standing target. Look for ways to open the central files and diagonals against it with checks and threats before it can shelter — every tempo the king spends in the middle is a chance for a combination.
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 f3, queen b5, rook c2, bishop d6, knight e5 a6, pawn a2 d2 h2.
Black: king e8, queen c6, rook h8, pawn d4 b6 f6 d7 g7 h7.
9 white and 9 black pieces are on the board; the puzzle position arises after move 23.
The position in numbers
White are ahead by 6 points of material (26 against 20; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f3, the black king on e8.
It is White to move on move 23, with 9 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 3 pawns, Black 6. Files fully open (no pawns of either colour): c, e — natural highways for the rooks and queen. Half-open for White: b, f, g.
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
23. Rxc6 fxe5 24. Qxe5+ Kf7 25. Qf5+ Ke8 26. Rc8#
Why it works
- Best move. rook to c6 is exactly what the engine plays (#3).
- Spot on — queen to e5 (#2).
- Precise: queen to f5 is the top choice (#1).
- Best move. rook to c8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead fxe5, then Qxe5+ and you win the queen.
Move by move
- 23. Rxc6 — rook to c6 (capture)
- fxe5 — pawn to e5 (capture)
- 24. Qxe5+ — queen to e5 (capture) with check
- Kf7 — king to f7
- 25. Qf5+ — queen to f5 with check
- Ke8 — king to e8
- 26. Rc8# — rook to c8 and it is checkmate
Types in this puzzle
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.
Relative pin
A piece shields a more valuable one behind it — moving it loses material.
In a relative pin the piece shields not its king but something valuable behind it, usually the queen. Moving is legal but costly, because the piece behind falls. Look for three units on one line: your long-range piece, a cheaper enemy piece, and an expensive one hiding behind. Beware the classic trap — a relatively pinned piece can still move with check or a bigger threat, so verify before you cash in.
Uncastled king
The king lingered in the middle — punish the delay.
Punishing the uncastled king: your opponent delayed castling, and now his king is stuck on its starting square under fire. In Chess960 this is deadlier than in classical chess — the king may start in the center or near the edge, and the familiar defensive setups simply do not apply. The signs: the victim still holds castling rights, and the files toward his king are half-open. Open lines before the king manages to hide.
About this position
These pieces come from starting position #514.
SP-514 · ThroneGuard — A centre-file king with no knight on the edge; a position and its mirror twin always share this family.
The king starts on e1, the rooks on b1 and h1, the queen on d1.
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.
The pawn on f2 is defended by the king alone — the classic soft spot of the standard setup.
The setup belongs to the ThroneGuard family; read right to left it becomes position 535.
The engine's main line opens with c4.
Morozov Balance Index: 96 of 100 — class A — most balanced. Engine evaluation of the starting position: +8 centipawns for White (depth 49, 400 000 000 nodes).
Explore position #514Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-514
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