Puzzle KBeL6 — ELO 2350
This is a White-to-move puzzle rated 2350 ELO. The first move is e6g4, tagged with 10 interpretable concepts and Lichess themes: backRankMate, mate, mateIn4.
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Position
White to move. ELO 2350. Themes: backRankMate, mate, mateIn4, middlegame, sacrifice, veryLong.
FEN: 1k1r1r2/ppp1b1p1/4B2p/8/4P1nP/2P5/PP4PR/R1B3K1 w - - 5 24
Show solution (8 ply)
Try to find the move yourself first — look for the rarest concept firing on this position before peeking. Solution sequence: e6g4 d8d1 g4d1 e7c5 c1e3 c5e3 g1h1 f8f1
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 Two white bishops cooperating to control critical squares near the enemy king…, which appears in only 48 of our 9,950 puzzles (0.48%). 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 2350 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?
2350 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 e6g4.
What concepts does it train?
10 SAE-derived patterns including Black king in a late endgame, frequently near the back…; A black bishop that is active or under pressure in a…; Detects a king on the back rank in a position with active….
Can I attempt it without an account?
Yes — Climbchess requires no signup or email. Click the trainer link to play the position interactively.