• 0.0 baseline — 0.6 × season 0.0 (5 gm) + 0.4 × last 10 0.1
• +0.0 opponent leak — they concede 33.1/game vs a 32.8 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• +1.0 wet forecast — averages 1 in the wet (8 gm)
• vs them: averages 0.9 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.