King under mating pressure, typically in a back-rank or anastasia mate pattern, with an attacking piece nearby and limited escape squares.
SAE concept sae_26406 fires when king under mating pressure, typically in a back-rank or anastasia mate pattern, with an attacking piece nearby and limited escape squares.. It appears in 8 of 9,950 Climbchess puzzles (0.1%), spanning ELO 724–2111 (median 2002).
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This page documents King under mating pressure, typically in 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:
King under mating pressure, typically in a back-rank or anastasia mate pattern, with an attacking piece nearby and limited escape squares.
This pattern fires in 8 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 724 to 2111, with a median rating of 2002. That distribution tells you whether this is a beginner cue or a master-level subtlety.
Pattern statistics
| Concept ID | sae_26406 |
|---|---|
| Puzzles where it fires | 8 |
| Min ELO | 724 |
| Median ELO | 2002 |
| Max ELO | 2111 |
| Coverage | 0.08% 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 8 puzzles spanning the rating distribution. Each links to its own page with full move list and related concepts.
- Puzzle st8SM — ELO 724, themes: crushing, endgame, interference, side to move: Black
- Puzzle st8SM_F — ELO 724, themes: crushing, endgame, interference, side to move: White
- Puzzle SiHuz — ELO 2002, themes: anastasiaMate, endgame, mate, side to move: White
- Puzzle SiHuz_F — ELO 2002, themes: anastasiaMate, endgame, mate, side to move: Black
- Puzzle SiHuz_M — ELO 2002, themes: anastasiaMate, endgame, mate, side to move: White
- Puzzle zfCs7 — ELO 2111, themes: advantage, discoveredAttack, discoveredCheck, side to move: White
- Puzzle zfCs7_F — ELO 2111, themes: advantage, discoveredAttack, discoveredCheck, side to move: Black
- Puzzle zfCs7_M — ELO 2111, themes: advantage, discoveredAttack, discoveredCheck, 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_26406?
King under mating pressure, typically in a back-rank or anastasia mate pattern, with an attacking piece nearby and limited escape squares. 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 8 tagged puzzles (0.1% of the set), spanning Lichess ELO 724 to 2111 with a median of 2002.
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.