Mate in 3: rook to c8 (e8)
c9-18927naming 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 b1, queen f3, rook e8, knight c4, pawn c2 h2 b3 g3 a4 e5.
Black: king a7, rook g6, knight c8, pawn a5 h5 b6 c7.
10 white and 7 black pieces are on the board; the puzzle position arises after move 40.
The position in numbers
White are ahead by 11 points of material (23 against 12; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on b1, the black king on a7.
It is White to move on move 40, with 45 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 4. Files fully open (no pawns of either colour): d, f — natural highways for the rooks and queen.
The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
40. Rxc8 Rc6 41. Qxc6 b5 42. Ra8#
Why it works
- Best move. rook to c8 is exactly what the engine plays (#2).
- Spot on — queen to c6 (#1).
- Precise: rook to a8 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Rc6, then Qxc6 and you win the rook.
Move by move
- 40. Rxc8 — rook to c8 (capture)
- Rc6 — rook to c6
- 41. Qxc6 — queen to c6 (capture)
- b5 — pawn to b5
- 42. Ra8# — rook to a8 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.
About this position
These pieces come from starting position #733.
SP-733 · RampartGuard — The king starts out on a wing file, b or g, with neither knight in a corner.
The king starts on b1, the rooks on a1 and h1, the queen on e1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
The bishops stand on d1 and g1; their long diagonals reach h5 and a7 once the e- and f-pawns step aside.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the RampartGuard family; read right to left it becomes position 424.
The engine's main line opens with a4.
Morozov Balance Index: 37 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +30 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #733Provenance
Mined from the project's engine self-play games.
Pack 012 · SP-733
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads