An undefended or lightly defended piece on an open square, vulnerable to a winning capture or tactical exploitation.
SAE concept sae_16450 fires when an undefended or lightly defended piece on an open square, vulnerable to a winning capture or tactical exploitation.. It appears in 84 of 9,950 Climbchess puzzles (0.8%), spanning ELO 627–2577 (median 1315).
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This page documents An undefended or lightly defended piece on an…, 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:
An undefended or lightly defended piece on an open square, vulnerable to a winning capture or tactical exploitation.
This pattern fires in 84 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 627 to 2577, with a median rating of 1315. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_16450 |
|---|---|
| Puzzles where it fires | 84 |
| Min ELO | 627 |
| Median ELO | 1315 |
| Max ELO | 2577 |
| Coverage | 0.84% 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 zznMe_M — ELO 627, themes: crushing, kingsideAttack, master, side to move: White
- Puzzle zx4cw_F — ELO 858, themes: advancedPawn, crushing, endgame, side to move: Black
- Puzzle zxsEL — ELO 885, themes: advancedPawn, advantage, endgame, side to move: Black
- Puzzle zAuJY_F — ELO 1021, themes: crushing, defensiveMove, endgame, side to move: Black
- Puzzle yePlW — ELO 1176, themes: crushing, endgame, long, side to move: Black
- Puzzle zoZTY — ELO 1315, themes: crushing, endgame, hangingPiece, side to move: White
- Puzzle zx1EE_M — ELO 1460, themes: crushing, defensiveMove, endgame, side to move: Black
- Puzzle 00IiM — ELO 1748, themes: advantage, middlegame, short, side to move: White
- Puzzle zxPtR — ELO 2039, themes: crushing, defensiveMove, endgame, side to move: Black
- Puzzle ze9kl — ELO 2462, 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_16450?
An undefended or lightly defended piece on an open square, vulnerable to a winning capture or tactical exploitation. 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 84 tagged puzzles (0.8% of the set), spanning Lichess ELO 627 to 2577 with a median of 1315.
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.