Winning blow: rook to d6 (c6·8)
c9-09662naming 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 4: a forced checkmate in four moves — every reply is covered.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 2350 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.
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.
This position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
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 h1 h8, rook c6, bishop a1 d1, knight c2 f5, pawn d2 e2 g2.
Black: king d7, rook b1, bishop d8, knight c3 e5, pawn c5 d5 e6 h7.
11 white and 9 black pieces are on the board; the puzzle position arises after move 21.
The position in numbers
White are ahead by 20 points of material (38 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 f1, the black king on d7.
It is White to move on move 21, with 47 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 4. Files fully open (no pawns of either colour): a, b, f — natural highways for the rooks and queen. Half-open for White: c, h.
White hold the bishop pair, an edge in open lines. The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
21. Rd6+ Kc8 22. Qxd8+ Kb7 23. Qxh7+ Nf7 24. Qxf7#
Why it works
- Best move. rook to d6 is exactly what the engine plays (#3).
- Spot on — queen to d8 (#2).
- Precise: queen to h7 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 Kc8, then Qxd8+ and you win the bishop.
Move by move
- 21. Rd6+ — rook to d6 with check
- Kc8 — king to c8
- 22. Qxd8+ — queen to d8 (capture) with check
- Kb7 — king to b7
- 23. Qxh7+ — queen to h7 (capture) with check
- Nf7 — knight to f7
- 24. Qxf7# — queen to f7 (capture) 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 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.
Win the pinned piece
The pinned piece cannot run — attack it again and win it.
A pinned piece cannot flee, which means you can win it outright by attacking it one more time. Count attackers against defenders: if you outnumber them, the piece is yours. The best extra attacker is a pawn, since it costs less than anything it might capture. Do not rush the capture — build up the pressure first, then harvest.
About this position
These pieces come from starting position #273.
SP-273 · ThroneGuard — Both knights start on inner files (b–g) while the king sits centrally on d or e — one of 204 positions filed here.
The king starts on e1, the rooks on c1 and g1, the queen on h1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
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: a2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 587.
The engine's main line opens with g4.
Morozov Balance Index: 7 of 100 — class D — largest edge. Engine evaluation of the starting position: +46 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #273Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-273
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