Chess960 tactic on f4 (c1)
c9-09797naming 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 a1, queen h8, bishop c1, knight g3, pawn c3 b4 a5.
Black: king b8, rook a7, bishop c8, pawn b5 c5 a6 h6.
7 white and 7 black pieces are on the board; the puzzle position arises after move 32.
The position in numbers
White are ahead by 6 points of material (18 against 12; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on a1, the black king on b8.
It is White to move on move 32, with 29 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 4. Files fully open (no pawns of either colour): d, e, f, g — natural highways for the rooks and queen. Half-open for White: h.
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
32. Bf4+ Kb7 33. Qd8 Kc6 34. Qd6+ Kb7 35. Qd5#
Why it works
- Best move. bishop to f4 is exactly what the engine plays (#3).
- queen to d8 develops smoothly.
- Precise: queen to d6 is the top choice (#1).
- Best move. queen to d5 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Kb7, then Qd8 and you stay on top.
Move by move
- 32. Bf4+ — bishop to f4 with check
- Kb7 — king to b7
- 33. Qd8 — queen to d8
- Kc6 — king to c6
- 34. Qd6+ — queen to d6 with check
- Kb7 — king to b7
- 35. Qd5# — queen to d5 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.
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 #903.
SP-903 · RampartGuard — King pushed to the b- or g-file, knights off the edges — 144 positions here.
The king starts on b1, the rooks on a1 and e1, the queen on d1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
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: f2.
The setup belongs to the RampartGuard family; read right to left it becomes position 50.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 14 of 100 — class D — largest edge. Engine evaluation of the starting position: +40 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #903Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-903
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