Chess960 tactic on d7 (d6·3)
c9-10477naming 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 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.
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 e2, queen c3, rook g1 d6, bishop c6, knight h1 d3, pawn a2 f2 g2 h2 e3 b5.
Black: king e7, rook g8, knight g6, pawn a4 h5 e6 f6 f7.
13 white and 8 black pieces are on the board; the puzzle position arises after move 21.
The position in numbers
White are ahead by 21 points of material (34 against 13; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on e2, the black king on e7.
It is White to move on move 21, with 55 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 5. Files fully open (no pawns of either colour): c, d — natural highways for the rooks and queen.
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
21. Rd7+ Ke8 22. Qxf6 Nf4+ 23. exf4 a3 24. Qxf7#
Why it works
- Great move! rook to d7 keeps the pressure (#3).
- Spot on — queen to f6 (#2).
- Precise: pawn to f4 is the top choice (#1).
- Best move. queen to f7 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Ke8, then Qxf6 and you stay on top.
Move by move
- 21. Rd7+ — rook to d7 with check
- Ke8 — king to e8
- 22. Qxf6 — queen to f6 (capture)
- Nf4+ — knight to f4 with check
- 23. exf4 — pawn to f4 (capture)
- a3 — pawn to a3
- 24. Qxf7# — queen to f7 (capture) 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.
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.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
About this position
These pieces come from starting position #585.
SP-585 · BastionScout — Off-centre king plus a rim knight (a/h): 168 positions carry this shape.
The king starts on f1, the rooks on b1 and g1, the queen on a1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
The bishops stand on d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the BastionScout family; read right to left it becomes position 281.
The engine's main line opens with O-O, bringing the king out to g1.
Morozov Balance Index: 69 of 100 — class B — balanced. Engine evaluation of the starting position: +21 centipawns for White (depth 42, 400 000 000 nodes).
Explore position #585Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-585
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