A black knight posted on a central or semi-central square (c4–f5 region), regardless of white pressure.
SAE concept sae_13581 fires when a black knight posted on a central or semi-central square (c4–f5 region), regardless of white pressure.. It appears in 772 of 9,950 Climbchess puzzles (7.8%), spanning ELO 642–2569 (median 1432).
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This page documents A black knight posted on a central or…, 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 black knight posted on a central or semi-central square (c4–f5 region), regardless of white pressure.
This pattern fires in 772 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 642 to 2569, with a median rating of 1432. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_13581 |
|---|---|
| Puzzles where it fires | 772 |
| Min ELO | 642 |
| Median ELO | 1432 |
| Max ELO | 2569 |
| Coverage | 7.76% 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 yql3v — ELO 642, themes: anastasiaMate, endgame, mate, side to move: Black
- Puzzle zvzWD — ELO 835, themes: kingsideAttack, mate, mateIn1, side to move: Black
- Puzzle 01L9G_M — ELO 933, themes: advantage, fork, middlegame, side to move: White
- Puzzle zmLdC_F — ELO 1091, themes: advantage, clearance, discoveredAttack, side to move: Black
- Puzzle zwZgL_F — ELO 1248, themes: advantage, attraction, endgame, side to move: Black
- Puzzle zy38n — ELO 1432, themes: advantage, attraction, endgame, side to move: Black
- Puzzle 01pJ3_M — ELO 1613, themes: crushing, endgame, knightEndgame, side to move: White
- Puzzle lb4F5 — ELO 1819, themes: backRankMate, clearance, deflection, side to move: Black
- Puzzle 016Ju — ELO 2097, themes: crushing, defensiveMove, endgame, side to move: White
- Puzzle zpOnX_M — ELO 2320, themes: crushing, discoveredAttack, long, 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_13581?
A black knight posted on a central or semi-central square (c4–f5 region), regardless of white pressure. 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 772 tagged puzzles (7.8% of the set), spanning Lichess ELO 642 to 2569 with a median of 1432.
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.