• 21.7 baseline — his last 10 games; only 3 this season, too few to blend
• +1.3 opponent leak — they concede 365.4/game vs a 344.7 league average
• +2.9 at this ground — averages 24.6 there (54 gm)
• vs them: averages 28.2 over 6 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.