• 167.3 baseline — 0.6 × season 164.7 (14 gm) + 0.4 × last 10 171.3
• +2.8 opponent leak — they concede 1715.2/game vs a 1686.6 league average
• −30.3 at this ground — averages 137 there (5 gm)
• −66.5 wet forecast — averages 100.9 in the wet (8 gm)
• vs them: averages 110.1 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. Round 5: 254 — far outside his usual range; kept in the average, not smoothed away.