Puzzle wVpo1_M — ELO 2284
This is a Black-to-move puzzle rated 2284 ELO. The first move is b7b1, tagged with 10 interpretable concepts and Lichess themes: backRankMate, exposedKing, fork.
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Position
Black to move. ELO 2284. Themes: backRankMate, exposedKing, fork, mate, mateIn5, middlegame, sacrifice, veryLong.
FEN: kr6/1r4np/p2R4/3pPp2/4qPP1/P6P/K3N3/6Q1 b - - 7 39
Show solution (18 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: b7b1 d6a6 a8b7 g1a7 b7c8 a6c6 c8d8 c6d6 d8e8 a7d7 e8f8 d6f6 f8g8 d7f7 g8h8 f7f8 b8f8 f6f8
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 Detects complex tactical positions where the side to move has undeveloped or…, which appears in only 174 of our 9,950 puzzles (1.75%). 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 2284 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?
2284 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 b7b1.
What concepts does it train?
10 SAE-derived patterns including A queen actively placed on an open rank or file relative…; Detects complex tactical positions where the side to move…; 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.