• 1.8 baseline — 0.6 × season 1.6 (17 gm) + 0.4 × last 10 2.0
• −0.0 opponent leak — they concede 154.7/game vs a 155.4 league average
• +0.1 at this ground — averages 1.9 there (9 gm)
• vs them: averages 3.5 over 2 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 17: 5 — far outside his usual range; kept in the average, not smoothed away.