Black rook actively placed in the opponent's half or mid-board, creating a discovered attack or check threat.

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

SAE concept sae_17405 fires when black rook actively placed in the opponent's half or mid-board, creating a discovered attack or check threat.. It appears in 4 of 9,950 Climbchess puzzles (0.0%), spanning ELO 796–2289 (median 2289).

Free forever · no email · no signup · delete data anytime.

This page documents Black rook actively placed in the opponent's…, 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 rook actively placed in the opponent's half or mid-board, creating a discovered attack or check threat.

This pattern fires in 4 of our 9,950 tagged puzzles. The puzzles where it appears span ELO 796 to 2289, with a median rating of 2289. 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:

• Rook endgame with active rook placement, often involving deflection… — similarity 0.103
• Active White rook threatening a decisive intrusion — 7th rank penetration or… — similarity 0.100
• Rook endgame where White has a positional or material advantage — connected… — similarity 0.091
• Pawn on the 4th, 5th, or 6th rank that is attacked by at least 2 enemy pieces… — similarity 0.016
• Rook actively placed in a mating or forcing configuration, often participating… — similarity 0.009

Example puzzles

Below are 4 puzzles spanning the rating distribution. Each links to its own page with full move list and related concepts.

• Puzzle y9L7e_M — ELO 796, themes: deflection, endgame, mate, side to move: White
• Puzzle zxVDE — ELO 2289, themes: crushing, defensiveMove, discoveredAttack, side to move: Black
• Puzzle zxVDE_F — ELO 2289, themes: crushing, defensiveMove, discoveredAttack, side to move: White
• Puzzle zxVDE_M — ELO 2289, themes: crushing, defensiveMove, discoveredAttack, 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).