• 4.2 baseline — 0.6 × season 3.9 (19 gm) + 0.4 × last 10 4.6
• +0.6 opponent leak — they concede 64.2/game vs a 56.6 league average
• −0.4 at this ground — averages 3.8 there (8 gm)
• wet forecast: too thin to count (1 gm) — shown, adds nothing
• vs them: averages 2.8 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 10: 10 — far outside his usual range; kept in the average, not smoothed away.