• 10.5 baseline — 0.6 × season 10.6 (20 gm) + 0.4 × last 10 10.4
• −0.7 opponent leak — they concede 345.4/game vs a 369 league average
• −2.3 at this ground — averages 8.3 there (4 gm)
• vs them: averages 10.8 over 4 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.