• 16.5 baseline — 0.6 × season 16.9 (17 gm) + 0.4 × last 10 16.0
• −0.2 opponent leak — they concede 363.9/game vs a 369 league average
• −0.9 at this ground — averages 15.7 there (6 gm)
• wet forecast: too thin to count (1 gm) — shown, adds nothing
• vs them: averages 14.3 over 4 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.