• 97.0 baseline — 0.6 × season 100.1 (15 gm) + 0.4 × last 10 92.3
• −1.4 opponent leak — they concede 1663.5/game vs a 1687.8 league average
• +31.2 at this ground — averages 128.2 there (27 gm)
• vs them: averages 106.3 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.