• 15.7 baseline — his last 10 games; only 1 this season, too few to blend
• +0.3 opponent leak — they concede 375.7/game vs a 369 league average
• +4.9 at this ground — averages 20.6 there (34 gm)
• vs them: averages 19.5 over 4 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.