An undefended white knight is under attack by a black piece, creating a tactical weakness that drives the solution.
SAE concept sae_2204 fires when an undefended white knight is under attack by a black piece, creating a tactical weakness that drives the solution.. It appears in 66 of 9,950 Climbchess puzzles (0.7%), spanning ELO 730–2551 (median 1101).
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This page documents An undefended white knight is under attack by a…, 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 white knight is under attack by a black piece, creating a tactical weakness that drives the solution.
This pattern fires in 66 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 730 to 2551, with a median rating of 1101. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_2204 |
|---|---|
| Puzzles where it fires | 66 |
| Min ELO | 730 |
| Median ELO | 1101 |
| Max ELO | 2551 |
| Coverage | 0.66% 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 z5QSy — ELO 730, themes: crushing, discoveredAttack, endgame, side to move: Black
- Puzzle zXfDF — ELO 769, themes: arabianMate, endgame, mate, side to move: White
- Puzzle zzf0W_M — ELO 849, themes: backRankMate, endgame, mate, side to move: Black
- Puzzle 01FzV_M — ELO 947, themes: crushing, endgame, fork, side to move: White
- Puzzle 00I8g_F — ELO 992, themes: crushing, endgame, short, side to move: Black
- Puzzle zz2hx_F — ELO 1101, themes: advantage, endgame, fork, side to move: White
- Puzzle 022JP_F — ELO 1309, themes: endgame, master, mate, side to move: White
- Puzzle xqxW0 — ELO 1462, themes: anastasiaMate, attraction, endgame, side to move: Black
- Puzzle 01EQu — ELO 1922, themes: crushing, endgame, knightEndgame, side to move: White
- Puzzle ypn11_F — ELO 2170, themes: endgame, mate, mateIn2, 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_2204?
An undefended white knight is under attack by a black piece, creating a tactical weakness that drives the solution. 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 66 tagged puzzles (0.7% of the set), spanning Lichess ELO 730 to 2551 with a median of 1101.
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.