• 3.8 baseline — his last 10 games; only 3 this season, too few to blend
• +0.2 opponent leak — they concede 164/game vs a 155.4 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• +1.4 wet forecast — averages 5.2 in the wet (14 gm)
• vs them: averages 5.3 over 7 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.