Chess960 tactic on d6 (d1·3)
c9-16676naming 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 e1, queen c6, rook d1 h1, bishop b3, knight h2, pawn g2 a3 e3 f3 h5.
Black: king f6, queen g7, rook d6 h8, knight c5, pawn e5 g5 b6 h6 c7.
11 white and 10 black pieces are on the board; the puzzle position arises after move 30.
The position in numbers
White are ahead by 3 points of material (30 against 27; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on e1, the black king on f6.
It is White to move on move 30, with 40 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): d — natural highways for the rooks and queen. Half-open for White: b, c.
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
30. Rxd6+ Ke7 31. Qxc7+ Nd7 32. Qxd7+ Kf8 33. Qd8#
Why it works
- Great move! rook to d6 keeps the pressure (#3).
- Well found: queen to c7 (#2).
- Precise: queen to d7 is the top choice (#1).
- Best move. queen to d8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Ke7, then Qxc7+ and you win the rook.
Move by move
- 30. Rxd6+ — rook to d6 (capture) with check
- Ke7 — king to e7
- 31. Qxc7+ — queen to c7 (capture) with check
- Nd7 — knight to d7
- 32. Qxd7+ — queen to d7 (capture) with check
- Kf8 — king to f8
- 33. Qd8# — queen to d8 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.
Win the pinned piece
The pinned piece cannot run — attack it again and win it.
A pinned piece cannot flee, which means you can win it outright by attacking it one more time. Count attackers against defenders: if you outnumber them, the piece is yours. The best extra attacker is a pawn, since it costs less than anything it might capture. Do not rush the capture — build up the pressure first, then harvest.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
About this position
These pieces come from starting position #552.
SP-552 · ThroneGuard — King on a central file (d/e) with both knights on inner files — the classic-type setup.
The king starts on d1, the rooks on a1 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 b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
One second-rank pawn starts with no defender at all: b2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 509.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 78 of 100 — class A — most balanced. Engine evaluation of the starting position: +18 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #552Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-552
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