• 187.9 baseline — 0.6 × season 185.2 (17 gm) + 0.4 × last 10 191.9
• +13.7 opponent leak — they concede 1810.8/game vs a 1687.8 league average
• −76.9 at this ground — averages 111 there (4 gm)
• vs them: averages 120.0 over 4 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. Round 22: 69 — far outside his usual range; kept in the average, not smoothed away.