Attack on the uncastled king: knight to h6 (g4·4)
c9-23530naming 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 in 3: a forced sequence that ends in checkmate.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Difficulty 1760 ShuffleRating — for advanced tacticians.
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.
In a mate in three every move must be forcing; the defender should never get a free tempo. Find the check or threat that herds the king, calculate the single defence to each, and confirm the net closes on the third move.
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 g1, queen g3, rook c1 f2, bishop b1, knight g4, pawn a2 g2 h3 c5 g7.
Black: king g8, queen a4, rook g5 c8, bishop b5, knight e6, pawn a7 f7.
11 white and 8 black pieces are on the board; the puzzle position arises after move 29.
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 g1, the black king on g8.
It is White to move on move 29, with 45 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 2. Files fully open (no pawns of either colour): b, d, e — natural highways for the rooks and queen. Half-open for White: f.
The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
29. Nh6+ Kxg7 30. Rxf7+ Kh8 31. Rh7#
Why it works
- Great move! knight to h6 keeps the pressure (#2).
- Well found: rook to f7 (#1).
- Precise: rook to h7 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kxg7, then Rxf7+ and you stay on top.
Move by move
- 29. Nh6+ — knight to h6 with check
- Kxg7 — king to g7 (capture)
- 30. Rxf7+ — rook to f7 (capture) with check
- Kh8 — king to h8
- 31. Rh7# — rook to h7 and it is checkmate
Types in this puzzle
Ladder mate
Two heavy pieces climb line by line, cutting off every retreat.
The ladder mate uses two heavy pieces climbing rung by rung: one cuts the king off along a line, the other checks on the next line, driving him toward the edge. It is the classic two-rook technique — check, the king retreats one rank, the other rook checks, until mate on the last rank. The only danger is the king creeping close enough to attack one of your rooks. If it does, simply slide that rook to the far side of the same line.
Mate in 3
A forced checkmate in three moves.
Mate in three is a forced staircase: each of your moves narrows the opponent's choices, and the third one ends the game. Look for the start among checks and sacrifices — quiet first moves are rare in mating problems, but deliciously sneaky. Keep the tree in your head: every defense gets its own branch. Do not stop calculating after move two — see the final mating picture with your own eyes.
Corner mate
Driven into the corner, the king runs out of squares.
The corner mate catches a king driven into the corner, where it has only three neighboring squares — all of them taken away or blocked. The corner is the worst home for a king, because the attacker needs to control the fewest squares there. Herd the king toward the corner with checks and never let it slip back toward the center. Cut off the escape routes before the final check, and the mate practically assembles itself.
About this position
These pieces come from starting position #416.
SP-416 · RampartGuard — A b- or g-file king and two knights on inner files (b–g).
The king starts on g1, the rooks on c1 and h1, the queen on e1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The pawn on g2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 735.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 24 of 100 — class D — largest edge. Engine evaluation of the starting position: +35 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #416Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-416
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads