Pawn endgame with a blocked or semi-blocked pawn majority on one wing, where zugzwang or king triangulation determines the outcome.

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

SAE concept sae_13732 fires when pawn endgame with a blocked or semi-blocked pawn majority on one wing, where zugzwang or king triangulation determines the outcome.. It appears in 13 of 9,950 Climbchess puzzles (0.1%), spanning ELO 831–2343 (median 1756).

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This page documents Pawn endgame with a blocked or semi-blocked pawn…, 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:

Pawn endgame with a blocked or semi-blocked pawn majority on one wing, where zugzwang or king triangulation determines the outcome.

This pattern fires in 13 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 831 to 2343, with a median rating of 1756. 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:

• Detects key contested squares in zugzwang pawn endgames where white has a… — similarity 0.231
• Detects contested squares where white holds equal or superior control… — similarity 0.214
• White passed pawn on the 5th rank in an endgame, undefended by white but not… — similarity 0.138
• Pawn endgame with a locked or near-locked pawn structure where zugzwang or a… — similarity 0.088
• Black pawn on the 6th rank in a king-and-pawn endgame, often a passed or… — similarity 0.077

Example puzzles

Below are 10 puzzles spanning the rating distribution. Each links to its own page with full move list and related concepts.

• Puzzle znXLk_M — ELO 831, themes: crushing, deflection, endgame, side to move: White
• Puzzle x3liZ — ELO 893, themes: bishopEndgame, crushing, defensiveMove, side to move: Black
• Puzzle x3liZ_F — ELO 893, themes: bishopEndgame, crushing, defensiveMove, side to move: White
• Puzzle zzz7H_M — ELO 1401, themes: crushing, endgame, long, side to move: Black
• Puzzle zQ7y4_F — ELO 1756, themes: crushing, endgame, long, side to move: White
• Puzzle zQ7y4_M — ELO 1756, themes: crushing, endgame, long, side to move: Black
• Puzzle 00MDy_M — ELO 1920, themes: crushing, endgame, long, side to move: White
• Puzzle zzm6T_F — ELO 2069, themes: crushing, defensiveMove, endgame, side to move: Black
• Puzzle zzm6T_M — ELO 2069, themes: crushing, defensiveMove, endgame, side to move: White
• Puzzle znZys — ELO 2343, themes: crushing, deflection, endgame, 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).