• 22.9 baseline — 0.6 × season 23.4 (15 gm) + 0.4 × last 10 22.1
• +2.1 opponent leak — they concede 594.5/game vs a 544.2 league average
• +1.9 at this ground — averages 24.8 there (33 gm)
• vs them: averages 22.3 over 7 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 7: 49 — far outside his usual range; kept in the average, not smoothed away.