• 6.6 baseline — 0.6 × season 7.2 (6 gm) + 0.4 × last 10 5.7
• +0.5 opponent leak — they concede 166.4/game vs a 155.4 league average
• −1.3 at this ground — averages 5.3 there (11 gm)
• wet forecast: too thin to count (2 gm) — shown, adds nothing
• vs them: averages 4.5 over 2 games — evidence, never summed

Most signals here point under while you're on the over — worth reading the working above before you commit.

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.