• 7.0 baseline — 0.6 × season 6.9 (13 gm) + 0.4 × last 10 7.0
• −0.2 opponent leak — they concede 357.8/game vs a 369 league average
• +0.7 at this ground — averages 7.6 there (14 gm)
• vs them: averages 7.0 over 5 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.