Puzzle zvsSK — ELO 2339
This is a Black-to-move puzzle rated 2339 ELO. The first move is a4d4, tagged with 10 interpretable concepts and Lichess themes: crushing, defensiveMove, deflection.
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Position
Black to move. ELO 2339. Themes: crushing, defensiveMove, deflection, endgame, long.
FEN: 6k1/4bp1p/1Bp1p1p1/2PpP1P1/q2P1QNP/8/2n2PK1/8 b - - 7 39
Show solution (6 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: a4d4 g4h6 g8h8 f4f7 c2e1 g2g1
Concepts that fire on this position
Our SAE pipeline tagged this position with 10 active features. Each links to a page documenting that pattern in detail.
Why this puzzle is hard
The rarest pattern firing here is White bishop actively placed on an open diagonal in a tactical mating…, which appears in only 65 of our 9,950 puzzles (0.65%). Rare patterns tend to be the bottleneck — players who haven't internalised them will fail this puzzle even when their tactical calculation is otherwise solid.
The puzzle's Lichess ELO of 2339 reflects this: solvers below that rating typically miss the cue entirely.
Similar puzzles
Puzzles sharing the most concept tags with this one — a stronger signal than theme overlap because it reflects the actual patterns Leela recognises.
Train this pattern
Click through to the Climbchess trainer to attempt the position interactively against the same Leela network that tagged it. The trainer adapts difficulty using your live concept-recognition profile — it surfaces puzzles tagged with concepts you've been missing, not random brawls.
If you want the underlying methodology, the how-it-works page walks through the SAE training run, the labelling pipeline, and the puzzle-tagging procedure end-to-end.
Frequently asked
What is the rating of this puzzle?
2339 Lichess ELO. Solvers below that rating typically miss the key cue.
Which side moves first?
Black to move; the first move of the solution is a4d4.
What concepts does it train?
10 SAE-derived patterns including A queen on a contested square with White to move, under…; A queen actively placed on an open rank or file relative…; A square on the 3rd rank is attacked by at least one black….
Can I attempt it without an account?
Yes — Climbchess requires no signup or email. Click the trainer link to play the position interactively.