• 35.3 baseline — 0.6 × season 30.6 (16 gm) + 0.4 × last 10 42.2
• +3.4 opponent leak — they concede 1851.3/game vs a 1686.6 league average
• +0.5 at this ground — averages 35.8 there (39 gm)
• vs them: averages 43.8 over 8 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.