• 7.2 baseline — 0.6 × season 7.1 (17 gm) + 0.4 × last 10 7.2
• −0.5 opponent leak — they concede 145.2/game vs a 155.4 league average
• −0.5 at this ground — averages 6.6 there (8 gm)
• vs them: averages 6.4 over 8 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 1: 1 — far outside his usual range; kept in the average, not smoothed away.