• 24.1 baseline — 0.6 × season 24.0 (20 gm) + 0.4 × last 10 24.2
• +0.3 opponent leak — they concede 349.4/game vs a 344.7 league average
• +1.6 at this ground — averages 25.7 there (23 gm)
• vs them: averages 23.7 over 11 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.