Winning blow: pawn to b5 (a4·15)
c9-20442naming 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.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1280 ShuffleRating — club-player level.
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 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 c1, rook b3, bishop h2, knight c6 e6, pawn a4 c5 d5.
Black: king a6, rook b7 d8, knight b5, pawn g2 g5 d6 e7.
8 white and 8 black pieces are on the board; the puzzle position arises after move 36.
The position in numbers
Material is level — 17 points of pieces on each side (pawn = 1, knight and bishop = 3, rook = 5, queen = 9).
The white king stands on c1, the black king on a6.
It is White to move on move 36, with 39 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 3 pawns, Black 4. Files fully open (no pawns of either colour): b, f, h — natural highways for the rooks and queen. Half-open for White: e, 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
36. axb5+ Rxb5 37. Ra3+ Ra5 38. Rxa5+
Why it works
- Great move! pawn to b5 keeps the pressure (#4).
- Well found: rook to a3 (#3).
- Strong! rook to a5 is the sharp choice (#2).
- You win a piece — the rook.
- If instead Rxb5, then Ra3+ and you stay on top.
Move by move
- 36. axb5+ — pawn to b5 (capture) with check
Types in this puzzle
Winning blow
Find the strike that wins material by force.
A winning blow is a forced material gain that does not fit a single textbook motif. The general tactical recipe applies: spot loose pieces, an awkwardly placed king, overloaded lines. Go through the forcing moves in order of violence — checks, captures, threats — because most combinations start with one of them. Do not judge by feel: calculate the concrete line until the outcome is beyond doubt.
About this position
These pieces come from starting position #863.
SP-863 · RampartGuard — A wing king (b/g) with no knight on the a- or h-file.
The king starts on b1, the rooks on a1 and d1, the queen on f1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
The pawn on b2 is defended by the king alone — the same soft spot f2 is in the classical setup.
The setup belongs to the RampartGuard family; read right to left it becomes position 96.
The engine's main line opens with a4.
Morozov Balance Index: 65 of 100 — class B — balanced. Engine evaluation of the starting position: +22 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #863Provenance
Mined from the project's engine self-play games.
Pack 009 · SP-863
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads