• 15.2 baseline — 0.6 × season 16.4 (5 gm) + 0.4 × last 10 13.4
• −0.2 opponent leak — they concede 364.1/game vs a 369 league average
• −1.2 at this ground — averages 14 there (4 gm)
• vs them: averages 8.0 over 1 game — 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.