• 34.5 baseline — 0.6 × season 33.4 (20 gm) + 0.4 × last 10 36.1
• −0.8 opponent leak — they concede 336.7/game vs a 344.7 league average
• at this ground: too thin to count (1 gm) — shown, adds nothing
• +5.2 wet forecast — averages 39.6 in the wet (11 gm)
• vs them: averages 36.2 over 10 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.