A pawn on its starting square (2nd rank for White, 7th for Black) that is attacked by at least one enemy piece and defended by at least one friendly piece.
SAE concept sae_13734 fires when a pawn on its starting square (2nd rank for White, 7th for Black) that is attacked by at least one enemy piece and defended by at least one friendly piece.. It appears in 31 of 9,950 Climbchess puzzles (0.3%), spanning ELO 724–2480 (median 1657).
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This page documents A pawn on its starting square (2nd rank for…, 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 pawn on its starting square (2nd rank for White, 7th for Black) that is attacked by at least one enemy piece and defended by at least one friendly piece.
This pattern fires in 31 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 724 to 2480, with a median rating of 1657. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_13734 |
|---|---|
| Puzzles where it fires | 31 |
| Min ELO | 724 |
| Median ELO | 1657 |
| Max ELO | 2480 |
| Coverage | 0.31% 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 yl8i2 — ELO 724, themes: crushing, middlegame, short, side to move: Black
- Puzzle 00piA_F — ELO 1110, themes: advantage, fork, middlegame, side to move: White
- Puzzle 01UeQ_F — ELO 1312, themes: advantage, long, middlegame, side to move: Black
- Puzzle 01Zgj_F — ELO 1593, themes: crushing, middlegame, short, side to move: Black
- Puzzle zv6eP_M — ELO 1642, themes: endgame, mate, mateIn1, side to move: White
- Puzzle zt6v3_M — ELO 1657, themes: crushing, hangingPiece, long, side to move: Black
- Puzzle zYcJS_M — ELO 1918, themes: advancedPawn, crushing, middlegame, side to move: Black
- Puzzle zyaaG_M — ELO 2080, themes: crushing, endgame, long, side to move: Black
- Puzzle 6pNhW_M — ELO 2125, themes: anastasiaMate, kingsideAttack, long, side to move: Black
- Puzzle 01jTV_M — ELO 2131, themes: crushing, master, 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_13734?
A pawn on its starting square (2nd rank for White, 7th for Black) that is attacked by at least one enemy piece and defended by at least one friendly piece. 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 31 tagged puzzles (0.3% of the set), spanning Lichess ELO 724 to 2480 with a median of 1657.
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.