Attack on the uncastled king: queen to f5 (f3·7)
c9-12824naming 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 f1, queen f3, rook a1 e4, bishop a3, knight d1 b3, pawn b2 f2 h2 d3 a4.
Black: king f8, queen h8, rook a8 g8, bishop b8 e8, knight c6, pawn d4 f5 d6 b7 g7.
12 white and 12 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
Material is level — 33 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on f1, the black king on f8.
It is White to move on move 17, with 41 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): c, e — natural highways for the rooks and queen. Half-open for White: g.
Black hold the bishop pair, an edge in open lines. The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
17. Qxf5+ Bf7 18. Qc8+ Nd8 19. Qxd8+ Be8 20. Qxe8#
Why it works
- Great move! queen to f5 keeps the pressure (#3).
- Well found: queen to c8 (#2).
- Strong! queen to d8 is the sharp choice (#1).
- Best move. queen to e8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Bf7, then Qc8+ and you stay on top.
Move by move
- 17. Qxf5+ — queen to f5 (capture) with check
- Bf7 — bishop to f7
- 18. Qc8+ — queen to c8 with check
- Nd8 — knight to d8
- 19. Qxd8+ — queen to d8 (capture) with check
- Be8 — bishop to e8
- 20. Qxe8# — queen to e8 (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.
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 #472.
SP-472 · BastionGuard — Both knights begin inside the board while the king stands on c or f; a position and its mirror twin share this family.
The king starts on f1, the rooks on a1 and g1, the queen on h1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
Every pawn on the second rank is defended from the very first move.
The setup belongs to the BastionGuard family; read right to left it becomes position 685.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 10 of 100 — class D — largest edge. Engine evaluation of the starting position: +43 centipawns for White (depth 43, 400 000 000 nodes).
Explore position #472Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-472
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