• 2.3 baseline — 0.6 × season 2.3 (13 gm) + 0.4 × last 10 2.2
• −0.3 opponent leak — they concede 80.8/game vs a 93.4 league average
• +0.7 at this ground — averages 3 there (14 gm)
• vs them: averages 2.0 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. Round 18: 6 — far outside his usual range; kept in the average, not smoothed away.