• 3.7 baseline — 0.6 × season 3.8 (20 gm) + 0.4 × last 10 3.6
• −0.4 opponent leak — they concede 50.6/game vs a 56.6 league average
• −0.8 at this ground — averages 2.9 there (25 gm)
• wet forecast: too thin to count (3 gm) — shown, adds nothing
• vs them: averages 1.7 over 3 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: 9 — far outside his usual range; kept in the average, not smoothed away.