• 6.6 baseline — 0.6 × season 6.5 (15 gm) + 0.4 × last 10 6.7
• −0.4 opponent leak — they concede 53.5/game vs a 56.6 league average
• −0.1 at this ground — averages 6.5 there (6 gm)
• vs them: averages 7.2 over 11 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.