Attack on the uncastled king: rook to g8 (g3·5)
c9-10491naming 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 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.
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 e2, queen c1, rook g3 h4, bishop b1 h8, knight e3, pawn a2 f2 h2 b3 h3 c5.
Black: king e8, rook d8, bishop c6 b8, pawn a5 b5 e6 c7 d7 f7 h7.
13 white and 11 black pieces are on the board; the puzzle position arises after move 17.
The position in numbers
White are ahead by 16 points of material (34 against 18; 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 e8.
It is White to move on move 17, with 60 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 7. Files fully open (no pawns of either colour): g — natural highways for the rooks and queen. Half-open for White: d, e.
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
17. Rg8+ Ke7 18. Nd5+ Bxd5 19. Qg5+ f6 20. Qxf6#
Why it works
- Best move. rook to g8 is exactly what the engine plays (#3).
- Spot on — knight to d5 (#2).
- Precise: queen to g5 is the top choice (#1).
- Best move. queen to f6 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Ke7, then Nd5+ and you stay on top.
Move by move
- 17. Rg8+ — rook to g8 with check
- Ke7 — king to e7
- 18. Nd5+ — knight to d5 with check
- Bxd5 — bishop to d5 (capture)
- 19. Qg5+ — queen to g5 with check
- f6 — pawn to f6
- 20. Qxf6# — queen to f6 (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 #672.
SP-672 · ThroneGuard — King on a central file (d/e) with both knights on inner files — the classic-type setup.
The king starts on e1, the rooks on d1 and h1, the queen on c1.
The queenside rook already stands on d1, so castling long moves only the king, from e1 to c1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 479.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 51 of 100 — class B — balanced. Engine evaluation of the starting position: +26 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #672Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-672
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