Detects a king under attack where the defending side has fewer or equal defenders on the king square, regardless of the king's proximity to its starting square.

By · · 3 min read · Updated May 8, 2026

SAE concept sae_30384 fires when detects a king under attack where the defending side has fewer or equal defenders on the king square, regardless of the king's proximity to its starting square.. It appears in 27 of 9,950 Climbchess puzzles (0.3%), spanning ELO 698–2551 (median 1386).

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This page documents Detects a king under attack where the defending…, 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:

Detects a king under attack where the defending side has fewer or equal defenders on the king square, regardless of the king's proximity to its starting square.

This pattern fires in 27 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 698 to 2551, with a median rating of 1386. That distribution tells you whether this is a beginner cue or a master-level subtlety.

Pattern statistics

Concept IDsae_30384
Puzzles where it fires27
Min ELO698
Median ELO1386
Max ELO2551
Coverage0.27% 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.

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_30384?

Detects a king under attack where the defending side has fewer or equal defenders on the king square, regardless of the king's proximity to its starting square. 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 27 tagged puzzles (0.3% of the set), spanning Lichess ELO 698 to 2551 with a median of 1386.

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.