White pawn on the 4th rank, attacked by white pieces, and not attacked by black pieces.

By Climbchess Research · 2026-05-08 · 3 min read · Updated May 8, 2026

SAE concept sae_4961 fires when white pawn on the 4th rank, attacked by white pieces, and not attacked by black pieces.. It appears in 1 of 9,950 Climbchess puzzles (0.0%), spanning ELO 920–920 (median 920).

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This page documents White pawn on the 4th rank, attacked by white…, 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:

White pawn on the 4th rank, attacked by white pieces, and not attacked by black pieces.

This pattern fires in 1 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 920 to 920, with a median rating of 920. That distribution tells you whether this is a beginner cue or a master-level subtlety.

Pattern statistics

Related concepts

The five concepts most often co-firing alongside this one (Jaccard similarity over the puzzle co-occurrence graph) are:

• A contested central square on ranks 3-5 that is attacked by at least one enemy… — similarity 0.059
• Detects an active black bishop in an endgame, typically on a central or… — similarity 0.008
• King on rank 2 or 7 in a simplified endgame, often with passed pawns or mating… — similarity 0.003
• White king on the back rank (e1–g1 area) in a tactical position with active… — similarity 0.001
• White bishop on home territory (ranks 1-3) in a standard development position… — similarity 0.001

Example puzzles

Below are 1 puzzles spanning the rating distribution. Each links to its own page with full move list and related concepts.

• Puzzle zw7Eb_M — ELO 920, themes: advantage, endgame, master, 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).