• 12.4 baseline — 0.6 × season 12.3 (14 gm) + 0.4 × last 10 12.5
• +0.7 opponent leak — they concede 164/game vs a 155.4 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• +0.3 wet forecast — averages 12.6 in the wet (14 gm)
• vs them: averages 17.6 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.