Mate in 3: rook to a1 (b1·4)
c9-26427naming 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 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.
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 c1, queen e7, rook b1 d1, bishop h1, knight e6, pawn b2 d2 b3 c3 e4 g4.
Black: king a6, queen h2, rook d8, bishop e5, knight f7, pawn b5 g6 h7.
12 white and 8 black pieces are on the board; the puzzle position arises after move 22.
The position in numbers
White are ahead by 8 points of material (31 against 23; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on a6.
It is White to move on move 22, with 35 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 3. Files fully open (no pawns of either colour): a, f — natural highways for the rooks and queen. Half-open for White: h.
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
22. Ra1+ Kb6 23. Qa7+ Kc6 24. Ra6#
Why it works
- Best move. rook to a1 is exactly what the engine plays (#2).
- Spot on — queen to a7 (#1).
- Precise: rook to a6 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kb6, then Qa7+ and you stay on top.
Move by move
- 22. Ra1+ — rook to a1 with check
- Kb6 — king to b6
- 23. Qa7+ — queen to a7 with check
- Kc6 — king to c6
- 24. Ra6# — rook to a6 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.
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
About this position
These pieces come from starting position #383.
SP-383 · BastionScout — King shifted to c or f, with a knight committed to the corner from move one.
The king starts on c1, the rooks on b1 and d1, the queen on f1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the BastionScout family; read right to left it becomes position 288.
The engine's main line opens with f4.
Morozov Balance Index: 26 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +34 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #383Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-383
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