• 23.2 baseline — 0.6 × season 22.5 (15 gm) + 0.4 × last 10 24.3
• +1.1 opponent leak — they concede 386.2/game vs a 369 league average
• −0.6 at this ground — averages 22.6 there (42 gm)
• vs them: averages 22.2 over 10 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.