Pawn on the 7th rank (any file) that is advanced or contested, often with promotion themes.
SAE concept sae_852 fires when pawn on the 7th rank (any file) that is advanced or contested, often with promotion themes.. It appears in 393 of 9,950 Climbchess puzzles (3.9%), spanning ELO 675–2696 (median 1614).
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This page documents Pawn on the 7th rank (any file) that is advanced…, 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:
Pawn on the 7th rank (any file) that is advanced or contested, often with promotion themes.
This pattern fires in 393 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 675 to 2696, with a median rating of 1614. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_852 |
|---|---|
| Puzzles where it fires | 393 |
| Min ELO | 675 |
| Median ELO | 1614 |
| Max ELO | 2696 |
| Coverage | 3.95% 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 zmWwx — ELO 675, themes: advancedPawn, endgame, hangingPiece, side to move: Black
- Puzzle zzNIE — ELO 807, themes: endgame, master, mate, side to move: White
- Puzzle zoek5_F — ELO 984, themes: advancedPawn, backRankMate, endgame, side to move: Black
- Puzzle zcA6j_F — ELO 1197, themes: advancedPawn, endgame, long, side to move: White
- Puzzle zhD42_M — ELO 1414, themes: advantage, bishopEndgame, deflection, side to move: Black
- Puzzle zniQF_F — ELO 1614, themes: advancedPawn, advantage, clearance, side to move: Black
- Puzzle 021wj_M — ELO 1702, themes: advancedPawn, crushing, endgame, side to move: White
- Puzzle zvdfa_M — ELO 1959, themes: advancedPawn, crushing, fork, side to move: Black
- Puzzle zw66m — ELO 2280, themes: advancedPawn, advantage, clearance, side to move: Black
- Puzzle zuTGU — ELO 2441, themes: crushing, endgame, 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_852?
Pawn on the 7th rank (any file) that is advanced or contested, often with promotion themes. 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 393 tagged puzzles (3.9% of the set), spanning Lichess ELO 675 to 2696 with a median of 1614.
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.