• 14.9 baseline — 0.6 × season 14.5 (19 gm) + 0.4 × last 10 15.5
• +1.4 opponent leak — they concede 233.1/game vs a 213.6 league average
• −1.2 at this ground — averages 13.7 there (21 gm)
• wet forecast: too thin to count (3 gm) — shown, adds nothing
• vs them: averages 11.3 over 3 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.