• 133.2 baseline — 0.6 × season 136.1 (18 gm) + 0.4 × last 10 128.9
• +2.3 opponent leak — they concede 1715.2/game vs a 1686.6 league average
• +47.5 at this ground — averages 180.7 there (7 gm)
• +31.9 wet forecast — averages 165.1 in the wet (11 gm)
• vs them: averages 177.5 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.