• 2.4 baseline — 0.6 × season 2.2 (15 gm) + 0.4 × last 10 2.6
• −0.1 opponent leak — they concede 33.9/game vs a 35.7 league average
• −0.7 at this ground — averages 1.7 there (15 gm)
• vs them: averages 3.0 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.