• 1.4 baseline — his last 10 games; only 2 this season, too few to blend
• +0.1 opponent leak — they concede 37.8/game vs a 35.7 league average
• +0.9 at this ground — averages 2.3 there (4 gm)
• vs them: averages 3.0 over 5 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.