Puzzle zzVXe_F — ELO 803
This is a White-to-move puzzle rated 803 ELO. The first move is f1c1, tagged with 10 interpretable concepts and Lichess themes: advantage, kingsideAttack, long.
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Position
White to move. ELO 803. Themes: advantage, kingsideAttack, long, middlegame.
FEN: 2r3k1/pp1n1pp1/2q1p1p1/3p4/3Pn3/1N1QPN1P/PP3PP1/5RK1 w - - 4 17
Show solution (6 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: f1c1 c6c1 b3c1 c8c1 d3f1 c1f1
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 This feature detects a white queen on a square that is attacked by both white…, which appears in only 20 of our 9,950 puzzles (0.20%). 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 803 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?
803 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 f1c1.
What concepts does it train?
10 SAE-derived patterns including A white rook on the back rank (rank 1), attacked by at…; 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.