Mate in 3: rook to b7 (b3·3)
c9-09975naming 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 2170 ShuffleRating — expert level — few solve it at first try.
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, rook e1 b3, bishop d4, knight d5, pawn a2 h2 d3 e3 a4 f4 h4.
Black: king g8, pawn a5 f5 g6.
12 white and 4 black pieces are on the board; the puzzle position arises after move 34.
The position in numbers
White are ahead by 20 points of material (23 against 3; 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 g8.
It is White to move on move 34, with 38 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 3. Files fully open (no pawns of either colour): b, c — natural highways for the rooks and queen. Half-open for White: g.
The White king has 5 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
34. Rb7 Kf8 35. Nf6 g5 36. Bc5#
Why it works
- Sensible development: rook to b7.
- knight to f6 develops smoothly.
- Precise: bishop to c5 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kf8, then Nf6 and you stay on top.
Move by move
- 34. Rb7 — rook to b7
- Kf8 — king to f8
- 35. Nf6 — knight to f6
- g5 — pawn to g5
- 36. Bc5# — bishop to c5 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.
Quiet move
No check, no capture — yet this modest move decides the game.
A quiet move gives no check and takes nothing — yet it decides the game by creating an unstoppable threat or stealing the king's last square. This is the hardest class of moves: the eye hunts for loud blows while a modest shift does the winning. The clue: every forcing try runs into a defense, so seek the move that strengthens the threat or takes squares away. Train yourself to ask: what if I neither capture nor check, but quietly improve?
About this position
These pieces come from starting position #94.
SP-94 · ThroneScout — A knight starts on the edge (a/h) and the king sits centrally on d or e; the mirror twin stays in this family too.
The king starts on d1, the rooks on c1 and e1, the queen on h1.
Castling long simply swaps the two pieces: the king on d1 and the rook on c1 trade places.
The bishops stand on f1 and g1; their long diagonals reach a6 and a7 once the e- and f-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, b2.
The setup belongs to the ThroneScout family; read right to left it becomes position 868.
The engine's main line opens with f4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 43, 400 000 000 nodes).
Explore position #94Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-94
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