• 14.9 baseline — 0.6 × season 14.6 (16 gm) + 0.4 × last 10 15.3
• +0.1 opponent leak — they concede 187.3/game vs a 186.3 league average
• +1.1 wet forecast — averages 16 in the wet (5 gm)
• vs them: averages 12.0 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 4: 6 — far outside his usual range; kept in the average, not smoothed away.