Puzzle zkHO1_M — ELO 2578
This is a Black-to-move puzzle rated 2578 ELO. The first move is e1e5, tagged with 10 interpretable concepts and Lichess themes: advancedPawn, crushing, endgame.
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Position
Black to move. ELO 2578. Themes: advancedPawn, crushing, endgame, promotion, quietMove, veryLong.
FEN: 4r2k/6pp/8/P2Q4/8/1P4P1/1KP4P/4q3 b - - 0 32
Show solution (18 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: e1e5 d5e5 e8e5 b3b4 e5e8 b4b5 e8a8 a5a6 h8g8 c2c4 g8f7 c4c5 f7e6 b5b6 a8a6 b6b7 a6a5 b7b8q
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 Kings are in close proximity in an endgame, with one side having a material or…, which appears in only 189 of our 9,950 puzzles (1.90%). 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 2578 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?
2578 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 e1e5.
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…; White Queen on the 1st or 2nd rank, unthreatened by black….
Can I attempt it without an account?
Yes — Climbchess requires no signup or email. Click the trainer link to play the position interactively.