• 2.1 baseline — 0.6 × season 2.2 (19 gm) + 0.4 × last 10 2.0
• +0.2 opponent leak — they concede 38.8/game vs a 35.7 league average
• vs them: averages 2.0 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.