• 6.7 baseline — 0.6 × season 7.1 (19 gm) + 0.4 × last 10 6.0
• −0.0 opponent leak — they concede 93.2/game vs a 93.4 league average
• −0.5 at this ground — averages 6.1 there (14 gm)
• vs them: averages 5.0 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 9: 13 — far outside his usual range; kept in the average, not smoothed away.