Black king in an active endgame role, often contesting key squares or supporting passed pawns, across various ranks.

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

SAE concept sae_24447 fires when black king in an active endgame role, often contesting key squares or supporting passed pawns, across various ranks.. It appears in 13 of 9,950 Climbchess puzzles (0.1%), spanning ELO 770–2295 (median 1262).

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This page documents Black king in an active endgame role, often…, 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:

Black king in an active endgame role, often contesting key squares or supporting passed pawns, across various ranks.

This pattern fires in 13 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 770 to 2295, with a median rating of 1262. 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:

• King opposition or key-square control in a king-and-pawn endgame, often… — similarity 0.130
• Trapped or misplaced black minor piece in an endgame, often a corner or edge… — similarity 0.094
• polysemantic — similarity 0.047
• Detects a king on the back rank or 7th rank in rook endgames, often with the… — similarity 0.038
• King active on central or near-central ranks (3rd–6th) in a king-and-pawn… — similarity 0.036

Example puzzles

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

• Puzzle LeYrW — ELO 770, themes: crushing, endgame, knightEndgame, side to move: Black
• Puzzle LeYrW_F — ELO 770, themes: crushing, endgame, knightEndgame, side to move: White
• Puzzle LeYrW_M — ELO 770, themes: crushing, endgame, knightEndgame, side to move: Black
• Puzzle sZhLw — ELO 879, themes: crushing, endgame, long, side to move: Black
• Puzzle sZhLw_M — ELO 879, themes: crushing, endgame, long, side to move: Black
• Puzzle zxO1P_M — ELO 1262, themes: crushing, defensiveMove, endgame, side to move: White
• Puzzle 01Jnn — ELO 2144, themes: crushing, endgame, pawnEndgame, side to move: Black
• Puzzle 01Jnn_M — ELO 2144, themes: crushing, endgame, pawnEndgame, side to move: Black
• Puzzle zfhn1 — ELO 2295, themes: bishopEndgame, crushing, defensiveMove, side to move: Black
• Puzzle zfhn1_F — ELO 2295, themes: bishopEndgame, crushing, defensiveMove, 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).