Puzzle zzhhc_M — ELO 1636
This is a Black-to-move puzzle rated 1636 ELO. The first move is d4b3, tagged with 10 interpretable concepts and Lichess themes: crushing, discoveredAttack, long.
Free forever · no email · no signup · delete data anytime.
Position
Black to move. ELO 1636. Themes: crushing, discoveredAttack, long, middlegame.
FEN: 1k1r2r1/1pp2pp1/p1q1bn1p/2b1p3/3nP1P1/1P1P3P/PBP1NQB1/1KRN3R b - - 6 16
Show solution (6 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: d4b3 c2b3 c5f2 c1c6 b7c6 d1f2
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 Black knight in the centre or on the 4th–7th rank, undefended and not attacked…, which appears in only 173 of our 9,950 puzzles (1.74%). 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 1636 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?
1636 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 d4b3.
What concepts does it train?
10 SAE-derived patterns including Detects white king safely castled on the back rank…; White Queen on the 1st or 2nd rank, unthreatened by black…; A queen actively placed on an open rank or file relative….
Can I attempt it without an account?
Yes — Climbchess requires no signup or email. Click the trainer link to play the position interactively.