• 8.0 baseline — 0.6 × season 7.7 (15 gm) + 0.4 × last 10 8.4
• +0.6 opponent leak — they concede 166.4/game vs a 155.4 league average
• −3.3 at this ground — averages 4.7 there (10 gm)
• vs them: averages 7.7 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 7: 14 — far outside his usual range; kept in the average, not smoothed away.