• 10.8 baseline — his last 10 games; only 1 this season, too few to blend
• −0.8 opponent leak — they concede 343.2/game vs a 369 league average
• +1.5 at this ground — averages 12.3 there (6 gm)
• vs them: averages 12.8 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.