• 32.0 baseline — 0.6 × season 28.7 (20 gm) + 0.4 × last 10 36.9
• +0.4 opponent leak — they concede 349.4/game vs a 344.7 league average
• −5.5 at this ground — averages 26.5 there (10 gm)
• vs them: averages 8.0 over 3 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.