Puzzle zzExe_F — ELO 1875
This is a White-to-move puzzle rated 1875 ELO. The first move is b2b3, tagged with 10 interpretable concepts and Lichess themes: crushing, endgame, pawnEndgame.
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Position
White to move. ELO 1875. Themes: crushing, endgame, pawnEndgame, short, zugzwang.
FEN: 8/8/4k3/2p5/2P1pp1p/2K4P/1P3PP1/8 w - - 0 40
Show solution (4 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: b2b3 e6e5 f2f3 e4e3
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 Pawn endgame or minor-piece endgame where control of a central outpost on…, which appears in only 21 of our 9,950 puzzles (0.21%). 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 1875 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?
1875 Lichess ELO. Solvers below that rating typically miss the key cue.
Which side moves first?
White to move; the first move of the solution is b2b3.
What concepts does it train?
10 SAE-derived patterns including Detects king opposition or a key king square in a pure…; King in an endgame position with no immediate threats…; Detects kings in near-opposition or close proximity in….
Can I attempt it without an account?
Yes — Climbchess requires no signup or email. Click the trainer link to play the position interactively.