• 7.0 baseline — 0.6 × season 6.8 (17 gm) + 0.4 × last 10 7.3
• −0.1 opponent leak — they concede 152.3/game vs a 155.4 league average
• +0.6 at this ground — averages 7.6 there (77 gm)
• vs them: averages 6.4 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.