• 6.7 baseline — 0.6 × season 6.8 (9 gm) + 0.4 × last 10 6.6
• +0.2 opponent leak — they concede 377.9/game vs a 369 league average
• +0.9 at this ground — averages 7.6 there (34 gm)
• vs them: averages 7.7 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.