• 8.0 baseline — 0.6 × season 7.9 (9 gm) + 0.4 × last 10 8.2
• +0.2 opponent leak — they concede 158.8/game vs a 155.4 league average
• +0.2 at this ground — averages 8.2 there (14 gm)
• vs them: averages 2.0 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. Round 9: 2 — far outside his usual range; kept in the average, not smoothed away.