• 10.1 baseline — 0.6 × season 9.1 (14 gm) + 0.4 × last 10 11.5
• +0.7 opponent leak — they concede 368.1/game vs a 344.9 league average
• +2.7 at this ground — averages 12.8 there (8 gm)
• vs them: averages 17.0 over 7 games — evidence, never summed

Derived, not measured — plain arithmetic over his real games, shown in full. Adjustments can overlap (a game at this ground can also be a wet one); they add simply, and this note is the admission.