• 7.8 baseline — 0.6 × season 8.0 (17 gm) + 0.4 × last 10 7.6
• −0.2 opponent leak — they concede 209.2/game vs a 213.6 league average
• −1.0 at this ground — averages 6.8 there (6 gm)
• wet forecast: too thin to count (1 gm) — shown, adds nothing
• vs them: averages 7.3 over 4 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 3: 15 — far outside his usual range; kept in the average, not smoothed away.