White's king's bishop on f1/c1, attacked by at least two white pieces and zero black pieces.
SAE concept sae_50 fires when white's king's bishop on f1/c1, attacked by at least two white pieces and zero black pieces.. It appears in 125 of 9,950 Climbchess puzzles (1.3%), spanning ELO 642–2692 (median 1349).
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This page documents White's king's bishop on f1/c1, attacked by at…, 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's king's bishop on f1/c1, attacked by at least two white pieces and zero black pieces.
This pattern fires in 125 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 642 to 2692, with a median rating of 1349. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_50 |
|---|---|
| Puzzles where it fires | 125 |
| Min ELO | 642 |
| Median ELO | 1349 |
| Max ELO | 2692 |
| Coverage | 1.26% 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 ytDY3 — ELO 642, themes: mate, mateIn1, oneMove, side to move: White
- Puzzle zwnUY_F — ELO 754, themes: kingsideAttack, mate, mateIn1, side to move: Black
- Puzzle zvIRu — ELO 897, themes: crushing, deflection, middlegame, side to move: White
- Puzzle zq1uH_M — ELO 1015, themes: clearance, kingsideAttack, mate, side to move: Black
- Puzzle zxfpV_M — ELO 1162, themes: advantage, opening, pin, side to move: White
- Puzzle zF3ww_F — ELO 1349, themes: clearance, crushing, middlegame, side to move: White
- Puzzle ztzVj — ELO 1469, themes: discoveredAttack, discoveredCheck, exposedKing, side to move: Black
- Puzzle zzcA6_M — ELO 1687, themes: crushing, master, masterVsMaster, side to move: White
- Puzzle zzzhg_M — ELO 1971, themes: crushing, hangingPiece, long, side to move: Black
- Puzzle zvXHb_F — ELO 2182, themes: exposedKing, kingsideAttack, long, 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_50?
White's king's bishop on f1/c1, attacked by at least two white pieces and zero black pieces. 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 125 tagged puzzles (1.3% of the set), spanning Lichess ELO 642 to 2692 with a median of 1349.
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.