A rook on its starting square (a1 or h1) that is not attacked, with the king on e1/e8 and no pieces between them, indicating the possibility of castling.
SAE concept sae_12172 fires when a rook on its starting square (a1 or h1) that is not attacked, with the king on e1/e8 and no pieces between them, indicating the possibility of castling.. It appears in 86 of 9,950 Climbchess puzzles (0.9%), spanning ELO 629–2625 (median 1422).
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This page documents A rook on its starting square (a1 or h1) that is…, 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:
A rook on its starting square (a1 or h1) that is not attacked, with the king on e1/e8 and no pieces between them, indicating the possibility of castling.
This pattern fires in 86 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 629 to 2625, with a median rating of 1422. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_12172 |
|---|---|
| Puzzles where it fires | 86 |
| Min ELO | 629 |
| Median ELO | 1422 |
| Max ELO | 2625 |
| Coverage | 0.86% 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 zyuwl — ELO 629, themes: mate, mateIn1, middlegame, side to move: Black
- Puzzle 00fK0_M — ELO 711, themes: mate, mateIn1, middlegame, side to move: Black
- Puzzle 01mms_F — ELO 968, themes: mate, mateIn1, middlegame, side to move: White
- Puzzle zzY87_F — ELO 1015, themes: advantage, discoveredAttack, kingsideAttack, side to move: White
- Puzzle X5r8Z_F — ELO 1263, themes: doubleBishopMate, mate, mateIn2, side to move: Black
- Puzzle 3MJuc — ELO 1422, themes: doubleBishopMate, mate, mateIn2, side to move: White
- Puzzle 027Il_F — ELO 1556, themes: crushing, kingsideAttack, middlegame, side to move: White
- Puzzle zzrqN_M — ELO 1768, themes: advantage, attraction, exposedKing, side to move: White
- Puzzle zyJTZ — ELO 1886, themes: advantage, deflection, middlegame, side to move: White
- Puzzle zxmow — ELO 2137, themes: advantage, clearance, middlegame, 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_12172?
A rook on its starting square (a1 or h1) that is not attacked, with the king on e1/e8 and no pieces between them, indicating the possibility of castling. 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 86 tagged puzzles (0.9% of the set), spanning Lichess ELO 629 to 2625 with a median of 1422.
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.