Mate in 3: rook to a8 (a1·3)
c9-21487naming 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 1980 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 d1, queen c2, rook a1, bishop h1 f2, knight b3 c4, pawn h2 f5.
Black: king c8, queen f4, rook e7, knight e2, pawn f3 c6 d6 b7 h7.
9 white and 9 black pieces are on the board; the puzzle position arises after move 29.
The position in numbers
White are ahead by 6 points of material (28 against 22; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on d1, the black king on c8.
It is White to move on move 29, with 46 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): a, e, g — natural highways for the rooks and queen. Half-open for White: b, c, d.
White hold the bishop pair, an edge in open lines. The White king has 1 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
29. Ra8+ Kc7 30. Bb6+ Kd7 31. Rd8#
Why it works
- Great move! rook to a8 keeps the pressure (#2).
- Well found: bishop to b6 (#1).
- Precise: rook to d8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kc7, then Bb6+ and you stay on top.
Move by move
- 29. Ra8+ — rook to a8 with check
- Kc7 — king to c7
- 30. Bb6+ — bishop to b6 with check
- Kd7 — king to d7
- 31. Rd8# — rook to d8 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.
About this position
These pieces come from starting position #735.
SP-735 · 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 f1, the queen on d1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
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 416.
The engine's main line opens with a4.
Morozov Balance Index: 20 of 100 — class D — largest edge. Engine evaluation of the starting position: +37 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #735Provenance
Mined from the project's engine self-play games.
Pack 014 · SP-735
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