White back-rank configuration with empty f1 attacked by multiple white pieces, typically with king on e1 or g1 and uncastled rooks.
SAE concept sae_35 fires when white back-rank configuration with empty f1 attacked by multiple white pieces, typically with king on e1 or g1 and uncastled rooks.. It appears in 24 of 9,950 Climbchess puzzles (0.2%), spanning ELO 667–2391 (median 1535).
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This page documents White back-rank configuration with empty f1…, one of 4,505 interpretable chess concepts extracted from Leela Chess Zero via sparse autoencoders. The full feature description from our SAE labelling pipeline reads:
White back-rank configuration with empty f1 attacked by multiple white pieces, typically with king on e1 or g1 and uncastled rooks.
This pattern fires in 24 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 667 to 2391, with a median rating of 1535. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_35 |
|---|---|
| Puzzles where it fires | 24 |
| Min ELO | 667 |
| Median ELO | 1535 |
| Max ELO | 2391 |
| Coverage | 0.24% of puzzle set |
Related concepts
The five concepts most often co-firing alongside this one (Jaccard similarity over the puzzle co-occurrence graph) are:
Example puzzles
Below are 10 puzzles spanning the rating distribution. Each links to its own page with full move list and related concepts.
- Puzzle zq34V — ELO 667, themes: backRankMate, mate, mateIn2, side to move: Black
- Puzzle 01VEo — ELO 745, themes: kingsideAttack, mate, mateIn1, side to move: White
- Puzzle 01VG0 — ELO 1006, themes: kingsideAttack, mate, mateIn1, side to move: White
- Puzzle 00zNz_F — ELO 1139, themes: mate, mateIn2, opening, side to move: White
- Puzzle zzf14_F — ELO 1323, themes: crushing, fork, long, side to move: White
- Puzzle zqyBZ — ELO 1535, themes: advantage, attraction, fork, side to move: White
- Puzzle 01hOX — ELO 1558, themes: crushing, middlegame, short, side to move: Black
- Puzzle zg6Wq — ELO 1983, themes: advantage, discoveredAttack, long, side to move: Black
- Puzzle ztNOg_F — ELO 2051, themes: advantage, clearance, defensiveMove, side to move: Black
- Puzzle zzUyc_F — ELO 2289, themes: advantage, defensiveMove, master, side to move: Black
How to use this page
If you want to train this pattern, open the Climbchess trainer and filter for puzzles tagged with this concept. The trainer surfaces them at the right difficulty for your current rating, and tracks how often you spot the cue versus miss it. You can also browse the related concepts above to see neighbouring ideas in feature space.
Climbchess concepts are not heuristics written by a human author. Each one corresponds to a single direction in the residual stream of Leela Chess Zero that activates on a specific board feature, then was labelled by reading the top-activating positions. This makes the catalogue exhaustive (every Leela-detectable pattern is in here somewhere) and falsifiable (you can replay our extraction).
Frequently asked
What is SAE concept sae_35?
White back-rank configuration with empty f1 attacked by multiple white pieces, typically with king on e1 or g1 and uncastled rooks. It is one of 4,505 interpretable features extracted from Leela Chess Zero's residual stream via sparse autoencoders, then labelled by reading the top-activating positions.
Where does this pattern appear?
In 24 tagged puzzles (0.2% of the set), spanning Lichess ELO 667 to 2391 with a median of 1535.
How do I train it?
Open the Climbchess trainer and filter for puzzles tagged with this concept. The trainer adapts difficulty using your live recognition profile and tracks how often you spot the cue versus miss it.
Is it free?
Yes. Climbchess is free forever, with no account, email, or signup required. You can delete your data at any time.