• 3.3 baseline — 0.6 × season 3.1 (14 gm) + 0.4 × last 10 3.6
• +0.3 opponent leak — they concede 25.8/game vs a 23.7 league average
• −1.7 at this ground — averages 1.6 there (5 gm)
• −2.3 wet forecast — averages 1 in the wet (8 gm)
• vs them: averages 2.4 over 10 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: 12 — far outside his usual range; kept in the average, not smoothed away.