Winning blow: queen to b6 (d8·3)
c9-09790naming 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 4: a forced checkmate in four moves — every reply is covered.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 2250 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.
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.
This position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
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 g1, queen d8, rook c1 a8, bishop b2, pawn a2 f2 g2.
Black: king d6, queen e2, bishop f4 d7, pawn f6 e7.
8 white and 6 black pieces are on the board; the puzzle position arises after move 33.
The position in numbers
White are ahead by 8 points of material (25 against 17; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on g1, the black king on d6.
It is White to move on move 33, with 42 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 2. Files fully open (no pawns of either colour): b, c, d, h — natural highways for the rooks and queen. Half-open for White: e.
Black 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
33. Qb6+ Kd5 34. Rc5+ Ke4 35. Qb4+ Kd3 36. Ra3#
Why it works
- Best move. queen to b6 is exactly what the engine plays (#3).
- Spot on — rook to c5 (#2).
- Precise: queen to b4 is the top choice (#1).
- Best move. rook to a3 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Kd5, then Rc5+ and you stay on top.
Move by move
- 33. Qb6+ — queen to b6 with check
- Kd5 — king to d5
- 34. Rc5+ — rook to c5 with check
- Ke4 — king to e4
- 35. Qb4+ — queen to b4 with check
- Kd3 — king to d3
- 36. Ra3# — rook to a3 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 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.
Counter-strike
Don't defend — answer the threat with a bigger one.
The counter-strike: instead of defending against the threat, you answer with a bigger threat of your own. While your opponent grabs a pawn, you deliver mate — the arithmetic favors you. Look for a counter when direct defenses fail: do you have a check, an attack on the queen, a mating threat? The beginner's error is meeting every threat with a reflexive defense without checking the counterattacking resources first.
About this position
These pieces come from starting position #20.
SP-20 · RampartScout — The king starts on b or g while a knight begins on the a- or h-file — the smallest family.
The king starts on g1, the rooks on f1 and h1, the queen on d1.
The king already stands on its castled square, so castling short moves only the rook, from h1 to f1.
The bishops stand on b1 and c1; their long diagonals reach h7 and h6 once the c- and d-pawns step aside.
Every pawn on the second rank is defended from the very first move.
The setup belongs to the RampartScout family; read right to left it becomes position 942.
The engine's main line opens with d4, 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 51, 400 000 000 nodes).
Explore position #20Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-20
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