King-and-pawn endgame decided by zugzwang, with no pieces other than kings and pawns.

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

SAE concept sae_5445 fires when king-and-pawn endgame decided by zugzwang, with no pieces other than kings and pawns.. It appears in 6 of 9,950 Climbchess puzzles (0.1%), spanning ELO 2111–2616 (median 2616).

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This page documents King-and-pawn endgame decided by zugzwang, 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:

King-and-pawn endgame decided by zugzwang, with no pieces other than kings and pawns.

This pattern fires in 6 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 2111 to 2616, with a median rating of 2616. That distribution tells you whether this is a beginner cue or a master-level subtlety.

Pattern statistics

Concept IDsae_5445
Puzzles where it fires6
Min ELO2111
Median ELO2616
Max ELO2616
Coverage0.06% 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 6 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_5445?

King-and-pawn endgame decided by zugzwang, with no pieces other than kings and pawns. 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 6 tagged puzzles (0.1% of the set), spanning Lichess ELO 2111 to 2616 with a median of 2616.

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.