Chess960 tactic on d6 (d1·5)
c9-13588naming 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.
A fork made possible by the Chess960 piece placement.
Difficulty 2400 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.
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.
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 b4, rook d1, knight b5 c8, pawn a2 b2 e3 h3 c4 f5.
Black: king d7, queen h6, bishop d6, pawn g4 h4 e5.
11 white and 6 black pieces are on the board; the puzzle position arises after move 31.
The position in numbers
White are ahead by 11 points of material (26 against 15; 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 d7.
It is White to move on move 31, with 37 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 3. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen. Half-open for White: g.
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
31. Rxd6+ Ke8 32. Rd8+ Kxd8 33. Qe7+ Kxc8 34. Qc7#
Why it works
- Best move. rook to d6 is exactly what the engine plays (#3).
- Spot on — rook to d8 (#2).
- Precise: queen to e7 is the top choice (#1).
- Best move. queen to c7 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Ke8, then Rd8+ and you win the bishop.
Move by move
- 31. Rxd6+ — rook to d6 (capture) with check
- Ke8 — king to e8
- 32. Rd8+ — rook to d8 with check
- Kxd8 — king to d8 (capture)
- 33. Qe7+ — queen to e7 with check
- Kxc8 — king to c8 (capture)
- 34. Qc7# — queen to c7 and it is checkmate
Types in this puzzle
Supported queen mate
The queen delivers mate face to face, protected by a friend.
The supported queen mate is the most common pattern of all: the queen lands next to the king and mates because a friendly piece or pawn protects her. The king is helpless — capturing is impossible, and the queen covers every neighboring square herself. Hunt for a protected square beside the enemy king: a knight, bishop or pawn eyeing it turns her invasion into mate. Verify one thing — that the square really is defended, or the king eats her.
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.
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.
About this position
These pieces come from starting position #74.
SP-74 · ThroneScout — The king starts on d or e while at least one knight begins in a corner.
The king starts on d1, the rooks on c1 and h1, the queen on g1.
Castling long simply swaps the two pieces: the king on d1 and the rook on c1 trade places.
The bishops stand on e1 and f1; their long diagonals reach a5 and a6 once the d- and e-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, b2.
The setup belongs to the ThroneScout family; read right to left it becomes position 885.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 55 of 100 — class B — balanced. Engine evaluation of the starting position: +25 centipawns for White (depth 49, 400 000 000 nodes).
Explore position #74Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-74
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