• 0.5 baseline — 0.6 × season 0.5 (18 gm) + 0.4 × last 10 0.5
• +0.2 opponent leak — they concede 12.3/game vs a 9.4 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• vs them: averages 0.0 over 1 game — 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.