• 0.4 baseline — 0.6 × season 0.4 (18 gm) + 0.4 × last 10 0.3
• +0.0 opponent leak — they concede 10.2/game vs a 9.4 league average
• −0.1 at this ground — averages 0.3 there (16 gm)
• −0.1 wet forecast — averages 0.3 in the wet (7 gm)
• vs them: averages 0.5 over 11 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 2: 3 — far outside his usual range; kept in the average, not smoothed away.