• 7.1 baseline — 0.6 × season 7.3 (8 gm) + 0.4 × last 10 6.8
• +0.2 opponent leak — they concede 219.6/game vs a 213.6 league average
• −0.2 at this ground — averages 6.9 there (30 gm)
• vs them: averages 5.7 over 6 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 17: 0 — far outside his usual range; kept in the average, not smoothed away.