A white piece attacks an undefended black piece on an open square, winning material — knight attacks also qualify.
SAE concept sae_38969 fires when a white piece attacks an undefended black piece on an open square, winning material — knight attacks also qualify.. It appears in 20 of 9,950 Climbchess puzzles (0.2%), spanning ELO 823–2623 (median 1405).
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This page documents A white piece attacks an undefended black piece…, 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 white piece attacks an undefended black piece on an open square, winning material — knight attacks also qualify.
This pattern fires in 20 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 823 to 2623, with a median rating of 1405. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_38969 |
|---|---|
| Puzzles where it fires | 20 |
| Min ELO | 823 |
| Median ELO | 1405 |
| Max ELO | 2623 |
| Coverage | 0.20% 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 qUkZX — ELO 823, themes: advantage, endgame, short, side to move: White
- Puzzle qUkZX_M — ELO 823, themes: advantage, endgame, short, side to move: White
- Puzzle 00QCD_F — ELO 1041, themes: advantage, middlegame, short, side to move: White
- Puzzle zzw8q — ELO 1324, themes: crushing, endgame, master, side to move: White
- Puzzle zzlgO — ELO 1405, themes: advantage, deflection, endgame, side to move: White
- Puzzle zzlgO_M — ELO 1405, themes: advantage, deflection, endgame, side to move: White
- Puzzle zkPWg_F — ELO 1673, themes: crushing, endgame, pawnEndgame, side to move: Black
- Puzzle zyqnN — ELO 1713, themes: crushing, defensiveMove, endgame, side to move: White
- Puzzle zvo9A — ELO 1946, themes: advantage, attraction, master, side to move: White
- Puzzle zhioD — ELO 2623, themes: crushing, defensiveMove, endgame, 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_38969?
A white piece attacks an undefended black piece on an open square, winning material — knight attacks also qualify. 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 20 tagged puzzles (0.2% of the set), spanning Lichess ELO 823 to 2623 with a median of 1405.
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.