Attack on the uncastled king: queen to d8 (d3·4)
c9-28512naming 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.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
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.
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 d3, rook a1 g1, bishop h1 c3, knight b3, pawn b2 c2 g3 a4 e4 f4 h4.
Black: king f8, queen b4, rook a8 g8, bishop h8, knight b8 c8, pawn a5 e5 b6 c6 g6 f7 h7.
14 white and 14 black pieces are on the board; the puzzle position arises after move 15.
The position in numbers
Material is level — 35 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 15, with 42 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 7. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen.
White hold the bishop pair, an edge in open lines. The White king has 6 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
15. Qd8+ Kg7 16. Bxe5+ f6 17. Qxf6+ Kh6 18. Qg5#
Why it works
- Great move! queen to d8 keeps the pressure (#3).
- Well found: bishop to e5 (#2).
- Strong! queen to f6 is the sharp choice (#1).
- Great move! queen to g5 keeps the pressure (#).
- The line ends in a forced mate in 4.
- If instead Kg7, then Bxe5+ and you stay on top.
Move by move
- 15. Qd8+ — queen to d8 with check
- Kg7 — king to g7
- 16. Bxe5+ — bishop to e5 (capture) with check
- f6 — pawn to f6
- 17. Qxf6+ — queen to f6 (capture) with check
- Kh6 — king to h6
- 18. Qg5# — queen to g5 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 #443.
SP-443 · BastionGuard — Off-centre king (c/f), no knight on the a- or h-file.
The king starts on f1, the rooks on a1 and g1, the queen on d1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
The second rank carries 2 pawns with no defender at all: b2, h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 705.
The engine's main line opens with c4.
Morozov Balance Index: 98 of 100 — class A — most balanced. Engine evaluation of the starting position: +5 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #443Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-443
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