• 17.2 baseline — 0.6 × season 17.2 (10 gm) + 0.4 × last 10 17.2
• −0.2 opponent leak — they concede 365.8/game vs a 369 league average
• −3.0 at this ground — averages 14.2 there (5 gm)
• vs them: averages 17.0 over 9 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.