• 1.4 baseline — 0.6 × season 1.5 (13 gm) + 0.4 × last 10 1.2
• −0.1 opponent leak — they concede 51/game vs a 56.6 league average
• −0.1 at this ground — averages 1.3 there (54 gm)
• vs them: averages 1.0 over 6 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.