• 11.7 baseline — 0.6 × season 12.1 (14 gm) + 0.4 × last 10 11.1
• +0.3 opponent leak — they concede 378.4/game vs a 369 league average
• −0.1 at this ground — averages 11.6 there (13 gm)
• vs them: averages 16.0 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.