Detects back-rank mate threats or endgame positions where black has a lone king on the back rank with limited escape squares.
SAE concept sae_24866 fires when detects back-rank mate threats or endgame positions where black has a lone king on the back rank with limited escape squares.. It appears in 513 of 9,950 Climbchess puzzles (5.2%), spanning ELO 621–2698 (median 1664).
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This page documents Detects back-rank mate threats or endgame…, 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:
Detects back-rank mate threats or endgame positions where black has a lone king on the back rank with limited escape squares.
This pattern fires in 513 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 621 to 2698, with a median rating of 1664. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_24866 |
|---|---|
| Puzzles where it fires | 513 |
| Min ELO | 621 |
| Median ELO | 1664 |
| Max ELO | 2698 |
| Coverage | 5.16% 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 veb0b — ELO 621, themes: arabianMate, endgame, mate, side to move: Black
- Puzzle zrLmb_F — ELO 823, themes: attackingF2F7, crushing, deflection, side to move: White
- Puzzle 01vaS — ELO 974, themes: mate, mateIn1, middlegame, side to move: Black
- Puzzle zuJP6_M — ELO 1190, themes: advantage, middlegame, short, side to move: Black
- Puzzle zqyBZ — ELO 1535, themes: advantage, attraction, fork, side to move: White
- Puzzle zzvNG_F — ELO 1664, themes: advancedPawn, kingsideAttack, mate, side to move: Black
- Puzzle zyJTZ — ELO 1886, themes: advantage, deflection, middlegame, side to move: White
- Puzzle zuVEI_F — ELO 2042, themes: advantage, hangingPiece, middlegame, side to move: Black
- Puzzle xdHy4_M — ELO 2200, themes: advantage, discoveredAttack, hangingPiece, side to move: White
- Puzzle pzHYo_F — ELO 2509, themes: crushing, long, middlegame, 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_24866?
Detects back-rank mate threats or endgame positions where black has a lone king on the back rank with limited escape squares. 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 513 tagged puzzles (5.2% of the set), spanning Lichess ELO 621 to 2698 with a median of 1664.
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.