• 9.9 baseline — his last 10 games; only 3 this season, too few to blend
• +0.3 opponent leak — they concede 219.2/game vs a 213.6 league average
• +2.7 at this ground — averages 12.6 there (43 gm)
• vs them: averages 12.5 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.