• 7.5 baseline — 0.6 × season 7.5 (19 gm) + 0.4 × last 10 7.6
• +0.3 opponent leak — they concede 160.7/game vs a 155.4 league average
• +0.8 at this ground — averages 8.3 there (10 gm)
• vs them: averages 4.0 over 1 game — 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 13: 15 — far outside his usual range; kept in the average, not smoothed away.