Black king on the back rank (a8–h8) with at least one black piece defending it and no white attackers.
SAE concept sae_4193 fires when black king on the back rank (a8–h8) with at least one black piece defending it and no white attackers.. It appears in 461 of 9,950 Climbchess puzzles (4.6%), spanning ELO 650–2696 (median 1562).
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This page documents Black king on the back rank (a8–h8) with 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:
Black king on the back rank (a8–h8) with at least one black piece defending it and no white attackers.
This pattern fires in 461 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 650 to 2696, with a median rating of 1562. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_4193 |
|---|---|
| Puzzles where it fires | 461 |
| Min ELO | 650 |
| Median ELO | 1562 |
| Max ELO | 2696 |
| Coverage | 4.63% 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 zx53p — ELO 650, themes: backRankMate, endgame, mate, side to move: White
- Puzzle ys3o2 — ELO 862, themes: arabianMate, endgame, kingsideAttack, side to move: Black
- Puzzle zzcZu_M — ELO 1068, themes: backRankMate, endgame, long, side to move: Black
- Puzzle z1Wz6 — ELO 1259, themes: anastasiaMate, attraction, kingsideAttack, side to move: Black
- Puzzle zMGTG — ELO 1481, themes: clearance, kingsideAttack, mate, side to move: White
- Puzzle ztjzc_F — ELO 1562, themes: arabianMate, endgame, mate, side to move: White
- Puzzle 027oG_M — ELO 1765, themes: crushing, endgame, short, side to move: White
- Puzzle zrxmw_F — ELO 1933, themes: deflection, kingsideAttack, long, side to move: White
- Puzzle ynVya_F — ELO 2140, themes: attraction, endgame, long, side to move: White
- Puzzle yxVd4_M — ELO 2433, themes: advantage, clearance, long, side to move: White
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_4193?
Black king on the back rank (a8–h8) with at least one black piece defending it and no white attackers. 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 461 tagged puzzles (4.6% of the set), spanning Lichess ELO 650 to 2696 with a median of 1562.
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.