Winning blow: king to d1 (c1·13)
c9-11489naming 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 1110 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 g1, bishop a1, pawn a2 c2 c3 h4 g7.
Black: king c8, rook h2, knight d6, pawn d2 h5 b6 a7 c7 d7.
8 white and 9 black pieces are on the board; the puzzle position arises after move 25.
The position in numbers
Black are ahead by 1 points of material (13 against 14; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on c1, the black king on c8.
It is White to move on move 25, with 3 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 5 pawns, Black 6. Files fully open (no pawns of either colour): e, f — natural highways for the rooks and queen. Half-open for White: b, d.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
25. Kd1 Kb7 26. g8=Q
Why it works
- Great move! king to d1 keeps the pressure (+5.2).
- Well found: pawn to g8 (+5.3).
- You win decisive material (+5.3).
- If instead Kb7, then g8=Q and you win the pawn.
Move by move
- 25. Kd1 — king to d1
- Kb7 — king to b7
- 26. g8=Q — pawn to g8
Types in this puzzle
Promotion
The pawn reaches the last rank and becomes a queen — decisively.
Promotion turns a pawn on the last rank into a queen and rewrites the evaluation on the spot. In tactics the passer rarely walks in for free — usually a sacrifice clears its path. Count the tempi: how many moves does the pawn need, and can the defender stop it in time? And watch the promotion square itself — it must be out of enemy reach or won by force in your combination.
Promotion race
Both sides push passers — win the race by a tempo.
A promotion race is a sprint between two passed pawns: both sides push toward the last rank, and victory goes to whoever queens first or queens with check. You will recognize it when both players have far-advanced passers that neither king can catch. Count the tempi literally, move by move, all the way to promotion. The classic mistake is spending a tempo on a "useful" move — in a race, almost any non-pawn move loses.
About this position
These pieces come from starting position #849.
SP-849 · BastionGuard — King shifted to c or f, knights kept clear of the edges — 168 positions in all.
The king starts on c1, the rooks on b1 and f1, the queen on h1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
One second-rank pawn starts with no defender at all: a2.
The setup belongs to the BastionGuard family; read right to left it becomes position 107.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 80 of 100 — class A — most balanced. Engine evaluation of the starting position: +17 centipawns for White (depth 45, 400 000 000 nodes).
Explore position #849Provenance
Mined from the project's engine self-play games.
Pack 007 · SP-849
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