A square singly controlled by a black piece with no white attackers, irrespective of side to move.
SAE concept sae_25275 fires when a square singly controlled by a black piece with no white attackers, irrespective of side to move.. It appears in 46 of 9,950 Climbchess puzzles (0.5%), spanning ELO 652–2524 (median 1702).
Free forever · no email · no signup · delete data anytime.
This page documents A square singly controlled by a black piece with…, 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 square singly controlled by a black piece with no white attackers, irrespective of side to move.
This pattern fires in 46 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 652 to 2524, with a median rating of 1702. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_25275 |
|---|---|
| Puzzles where it fires | 46 |
| Min ELO | 652 |
| Median ELO | 1702 |
| Max ELO | 2524 |
| Coverage | 0.46% 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 xazEV — ELO 652, themes: attraction, endgame, mate, side to move: Black
- Puzzle 00lMW_F — ELO 670, themes: endgame, mate, mateIn1, side to move: White
- Puzzle 01yBL — ELO 1308, themes: advantage, endgame, long, side to move: Black
- Puzzle zz5in_F — ELO 1328, themes: crushing, endgame, hangingPiece, side to move: Black
- Puzzle y4AjL_M — ELO 1439, themes: attraction, hookMate, mate, side to move: White
- Puzzle zzzco — ELO 1702, themes: endgame, mate, mateIn2, side to move: White
- Puzzle zzfDS_F — ELO 1717, themes: deflection, endgame, master, side to move: Black
- Puzzle zxBc5_F — ELO 1799, themes: advantage, endgame, pin, side to move: White
- Puzzle 01LIu — ELO 1835, themes: crushing, endgame, master, side to move: White
- Puzzle ncnsw_F — ELO 2183, themes: arabianMate, endgame, mate, 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_25275?
A square singly controlled by a black piece with no white attackers, irrespective of side to move. 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 46 tagged puzzles (0.5% of the set), spanning Lichess ELO 652 to 2524 with a median of 1702.
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.