• 2.3 baseline — 0.6 × season 2.2 (9 gm) + 0.4 × last 10 2.4
• −0.0 opponent leak — they concede 93.2/game vs a 93.4 league average
• +1.9 at this ground — averages 4.2 there (43 gm)
• vs them: averages 4.5 over 6 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.