Mate in 3: rook to f8 (f1·2)
c9-18982naming 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.
Difficulty 1630 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.
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 a1, queen d2, rook c1 f1, bishop b3, knight c5, pawn e2 d4.
Black: king c8, queen g2, rook d7 b8, bishop h5, pawn a3 g3 c7 g7 h7.
8 white and 10 black pieces are on the board; the puzzle position arises after move 29.
The position in numbers
Material is level — 27 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on a1, the black king on c8.
It is White to move on move 29, with 51 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 2 pawns, Black 5. Files fully open (no pawns of either colour): b, f — natural highways for the rooks and queen. Half-open for White: a, c, g, h.
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. Rf8+ Be8 30. Rxe8+ Rd8 31. Be6#
Why it works
- Best move. rook to f8 is exactly what the engine plays (#2).
- Spot on — rook to e8 (#1).
- Precise: bishop to e6 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Be8, then Rxe8+ and you win the bishop.
Move by move
- 29. Rf8+ — rook to f8 with check
- Be8 — bishop to e8
- 30. Rxe8+ — rook to e8 (capture) with check
- Rd8 — rook to d8
- 31. Be6# — bishop to e6 and it is checkmate
Types in this puzzle
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.
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 #729.
SP-729 · RampartGuard — King pushed to the b- or g-file, knights off the edges — 144 positions here.
The king starts on b1, the rooks on a1 and h1, the queen on f1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
The bishops stand on d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
The pawn on b2 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 425.
The engine's main line opens with e4, 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 47, 400 000 000 nodes).
Explore position #729Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-729
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