Mate in 3: rook to b7 (b1·8)
c9-22577naming 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 e6, rook b1 h1, pawn a2 f2 a3 c3 f3 h4 f5.
Black: king f8, rook g8, bishop e7, pawn d3 c6 h6 a7 b7.
11 white and 8 black pieces are on the board; the puzzle position arises after move 24.
The position in numbers
White are ahead by 13 points of material (26 against 13; 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 f8.
It is White to move on move 24, with 39 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 5. Files fully open (no pawns of either colour): e, g — natural highways for the rooks and queen. Half-open for White: b, d.
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
24. Rxb7 Rg5 25. Qxe7+ Kg8 26. Rb8#
Why it works
- Best move. rook to b7 is exactly what the engine plays (#2).
- Spot on — queen to e7 (#1).
- Precise: rook to b8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Rg5, then Qxe7+ and you win the bishop.
Move by move
- 24. Rxb7 — rook to b7 (capture)
- Rg5 — rook to g5
- 25. Qxe7+ — queen to e7 (capture) with check
- Kg8 — king to g8
- 26. Rb8# — rook to b8 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 #693.
SP-693 · 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 a1 and h1, the queen on b1.
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.
The bishops stand on c1 and d1; their long diagonals reach h6 and h5 once the d- and e-pawns step aside.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 458.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 69 of 100 — class B — balanced. Engine evaluation of the starting position: +21 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #693Provenance
Mined from the project's engine self-play games.
Pack 014 · SP-693
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