Puzzle zX40f_M — ELO 2349
This is a Black-to-move puzzle rated 2349 ELO. The first move is d6e6, tagged with 10 interpretable concepts and Lichess themes: crushing, endgame, long.
Free forever · no email · no signup · delete data anytime.
Position
Black to move. ELO 2349. Themes: crushing, endgame, long, pawnEndgame, zugzwang.
FEN: 8/8/pppk4/7p/1PPK2p1/P5P1/6P1/8 b - - 0 33
Show solution (6 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: d6e6 c4c5 b6b5 d4e4 e6f6 e4f4
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 A passed pawn on the 5th rank is defended by a friendly piece and not under…, which appears in only 60 of our 9,950 puzzles (0.60%). 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 2349 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?
2349 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 d6e6.
What concepts does it train?
10 SAE-derived patterns including Active king in a king-and-pawn endgame, often on the…; 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.