Mate in 3: pawn to a5
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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 g2, queen c8, rook d1 e1, bishop g4, pawn c2 h2 c3 g3 a4 b4 f4.
Black: king b6, queen h6, rook f7 a8, bishop g8, knight b8, pawn c6 d6 f6 g6 a7 b7 h7.
12 white and 13 black pieces are on the board; the puzzle position arises after move 23.
The position in numbers
Black are ahead by 3 points of material (29 against 32; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g2, the black king on b6.
It is White to move on move 23, with 47 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 7. Files fully open (no pawns of either colour): e — natural highways for the rooks and queen. Half-open for White: d.
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
23. a5+ Kb5 24. Be2+ Ka4 25. Ra1#
Why it works
- Great move! pawn to a5 keeps the pressure (#2).
- Well found: bishop to e2 (#1).
- Precise: rook to a1 is the top choice (#).
- The line ends in a forced mate in 3.
- If instead Kb5, then Be2+ and you stay on top.
Move by move
- 23. a5+ — pawn to a5 with check
- Kb5 — king to b5
- 24. Be2+ — bishop to e2 with check
- Ka4 — king to a4
- 25. Ra1# — rook to a1 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 #447.
SP-447 · 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 f1, the queen on d1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
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: b2.
The setup belongs to the ThroneGuard family; read right to left it becomes position 704.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 43 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +28 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #447Provenance
Mined from the project's engine self-play games.
Pack 013 · SP-447
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