• 92.0 baseline — 0.6 × season 90.3 (7 gm) + 0.4 × last 10 94.6
• +8.9 opponent leak — they concede 1851.3/game vs a 1687.8 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• vs them: averages 100.8 over 8 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.