• 2.1 baseline — his last 10 games; only 3 this season, too few to blend
• −0.0 opponent leak — they concede 154.7/game vs a 155.4 league average
• −0.4 at this ground — averages 1.8 there (8 gm)
• vs them: averages 3.0 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.