Detects a king on the target square that is not attacked by the opponent, especially when the king is on its starting square or in the endgame.
SAE concept sae_19898 fires when detects a king on the target square that is not attacked by the opponent, especially when the king is on its starting square or in the endgame.. It appears in 3,950 of 9,950 Climbchess puzzles (39.7%), spanning ELO 610–2698 (median 1552).
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This page documents Detects a king on the target square that is not…, 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 a king on the target square that is not attacked by the opponent, especially when the king is on its starting square or in the endgame.
This pattern fires in 3,950 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 610 to 2698, with a median rating of 1552. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_19898 |
|---|---|
| Puzzles where it fires | 3,950 |
| Min ELO | 610 |
| Median ELO | 1552 |
| Max ELO | 2698 |
| Coverage | 39.70% 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 xRhy5 — ELO 610, themes: advantage, endgame, master, side to move: Black
- Puzzle zhtaT_M — ELO 835, themes: hangingPiece, mate, mateIn1, side to move: White
- Puzzle 00cud — ELO 960, themes: crushing, endgame, fork, side to move: Black
- Puzzle zlHo0 — ELO 1152, themes: backRankMate, endgame, long, side to move: White
- Puzzle zyF98_F — ELO 1317, themes: exposedKing, long, mate, side to move: White
- Puzzle 00LH7 — ELO 1552, themes: crushing, endgame, short, side to move: Black
- Puzzle zq18C — ELO 1720, themes: advancedPawn, advantage, endgame, side to move: Black
- Puzzle zukpx_F — ELO 1942, themes: advantage, deflection, middlegame, side to move: White
- Puzzle zbvtj — ELO 2176, themes: endgame, long, master, side to move: Black
- Puzzle AChc6 — ELO 2424, themes: attraction, deflection, discoveredAttack, 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_19898?
Detects a king on the target square that is not attacked by the opponent, especially when the king is on its starting square or in the endgame. 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 3,950 tagged puzzles (39.7% of the set), spanning Lichess ELO 610 to 2698 with a median of 1552.
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.