• 1.8 baseline — his last 10 games; only 2 this season, too few to blend
• +0.2 opponent leak — they concede 64.2/game vs a 56.6 league average
• −1.1 at this ground — averages 0.7 there (6 gm)
• vs them: averages 1.0 over 2 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.