• 36.2 baseline — 0.6 × season 36.6 (18 gm) + 0.4 × last 10 35.7
• +2.2 opponent leak — they concede 365.4/game vs a 344.7 league average
• −12.8 at this ground — averages 23.4 there (47 gm)
• vs them: averages 27.5 over 4 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.