• 3.0 baseline — 0.6 × season 2.8 (16 gm) + 0.4 × last 10 3.3
• +0.2 opponent leak — they concede 368.1/game vs a 344.9 league average
• +2.2 at this ground — averages 5.2 there (6 gm)
• vs them: averages 3.3 over 11 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 13: 8 — far outside his usual range; kept in the average, not smoothed away.