• 22.6 baseline — 0.6 × season 21.7 (18 gm) + 0.4 × last 10 23.8
• +0.3 opponent leak — they concede 349.4/game vs a 344.9 league average
• at this ground: too thin to count (1 gm) — shown, adds nothing
• vs them: averages 24.2 over 5 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.