• 36.9 baseline — 0.6 × season 39.5 (16 gm) + 0.4 × last 10 33.1
• −0.3 opponent leak — they concede 539.6/game vs a 544.2 league average
• +11.1 at this ground — averages 48 there (10 gm)
• vs them: averages 35.3 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.