Chess960 tactic on a8 (a3)
c9-13744naming 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: a forcing sequence that ends the game — the king has no escape.
Mate in 4: a forced checkmate in four moves — every reply is covered.
Difficulty 2400 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.
This is a forced mating attack. Start from the enemy king: which of its squares are already covered, and which move takes away the rest while keeping the king in check? Forcing moves — checks and captures — are what turn an attack into mate.
A mate in four is a longer forced net: each of your moves is a check or an irresistible threat, and the king is driven step by step to a square where it is finally trapped. Verify that the defender has exactly one reply at every branch.
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 h1, queen d8, rook f1 a3, bishop f3 h8, pawn b2 g2 h2 b4 d5.
Black: king f7, queen f4, bishop f5, knight a1, pawn d6 f6 g6 e7 h7.
11 white and 9 black pieces are on the board; the puzzle position arises after move 24.
The position in numbers
White are ahead by 10 points of material (30 against 20; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on h1, the black king on f7.
It is White to move on move 24, with 44 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 5. Files fully open (no pawns of either colour): a, c — natural highways for the rooks and queen. Half-open for White: e, f.
White hold the bishop pair, an edge in open lines. 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
24. Ra8 Bc8 25. Qxc8 Qxh2+ 26. Kxh2 e5 27. Qe6#
Why it works
- Sensible development: rook to a8.
- Spot on — queen to c8 (#2).
- Precise: king to h2 is the top choice (#1).
- Best move. queen to e6 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Bc8, then Qxc8 and you win the bishop.
Move by move
- 24. Ra8 — rook to a8
- Bc8 — bishop to c8
- 25. Qxc8 — queen to c8 (capture)
- Qxh2+ — queen to h2 (capture) with check
- 26. Kxh2 — king to h2 (capture)
- e5 — pawn to e5
- 27. Qe6# — queen to e6 and it is checkmate
Types in this puzzle
Supported queen mate
The queen delivers mate face to face, protected by a friend.
The supported queen mate is the most common pattern of all: the queen lands next to the king and mates because a friendly piece or pawn protects her. The king is helpless — capturing is impossible, and the queen covers every neighboring square herself. Hunt for a protected square beside the enemy king: a knight, bishop or pawn eyeing it turns her invasion into mate. Verify one thing — that the square really is defended, or the king eats her.
Mate in 4+
A long forced mating combination.
Mate in four or longer is a marathon of forcing moves where the grip must never loosen. The tools are the same: checks, double threats and sacrifices that deny the opponent a single free tempo. Do not juggle the whole tree at once — walk the main line all the way to mate first, then verify the side branches. If somewhere the defender finds one quiet move that holds, your very first move was wrong.
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 #73.
SP-73 · BastionScout — A c- or f-file king with at least one knight out on the edge.
The king starts on f1, the rooks on c1 and h1, the queen on g1.
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 d1 and e1; their long diagonals reach h5 and a5 once the e- and d-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, b2.
The setup belongs to the BastionScout family; read right to left it becomes position 889.
The engine's main line opens with b4.
Morozov Balance Index: 34 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +31 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #73Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-73
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads