• 1.9 baseline — 0.6 × season 2.0 (20 gm) + 0.4 × last 10 1.8
• −0.0 opponent leak — they concede 185.2/game vs a 185.9 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• +3.4 wet forecast — averages 5.3 in the wet (13 gm)
• vs them: averages 5.2 over 11 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.