A white knight on c3 or f3 that is attacked by at least one white piece and not attacked by any black pieces.

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

SAE concept sae_6279 fires when a white knight on c3 or f3 that is attacked by at least one white piece and not attacked by any black pieces.. It appears in 2 of 9,950 Climbchess puzzles (0.0%), spanning ELO 2062–2062 (median 2062).

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This page documents A white knight on c3 or f3 that is attacked by…, 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:

A white knight on c3 or f3 that is attacked by at least one white piece and not attacked by any black pieces.

This pattern fires in 2 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 2062 to 2062, with a median rating of 2062. 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 white knight on rank 3, uncontested by black, in an active tactical or… — similarity 0.004
• A square dominated by a white knight where white has equal or superior control… — similarity 0.003
• Detects positions with an active white knight on an outpost square (typically… — similarity 0.003
• A white knight on a stable central or near-central square, participating in an… — similarity 0.002
• An uncastled rook on the back rank that retains castling rights, with no… — similarity 0.002

Example puzzles

Below are 2 puzzles spanning the rating distribution. Each links to its own page with full move list and related concepts.

• Puzzle 01PlY — ELO 2062, themes: crushing, long, middlegame, side to move: White
• Puzzle 01PlY_F — ELO 2062, themes: crushing, long, middlegame, 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).