• 1.8 baseline — 0.6 × season 1.8 (14 gm) + 0.4 × last 10 1.8
• +0.1 opponent leak — they concede 160.7/game vs a 155.4 league average
• +1.2 at this ground — averages 3 there (46 gm)
• vs them: averages 2.3 over 7 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 8: 5 — far outside his usual range; kept in the average, not smoothed away.