• 10.9 baseline — his last 10 games; only 2 this season, too few to blend
• +0.9 opponent leak — they concede 399.5/game vs a 369 league average
• +0.4 at this ground — averages 11.3 there (7 gm)
• vs them: averages 15.0 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.