• 3.0 baseline — 0.6 × season 2.7 (15 gm) + 0.4 × last 10 3.3
• −0.0 opponent leak — they concede 544.7/game vs a 545.7 league average
• +3.8 at this ground — averages 6.8 there (25 gm)
• vs them: averages 9.5 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 22: 10 — far outside his usual range; kept in the average, not smoothed away.