• 1.2 baseline — 0.6 × season 1.2 (11 gm) + 0.4 × last 10 1.3
• +0.2 opponent leak — they concede 64.2/game vs a 56.6 league average
• −0.1 at this ground — averages 1.1 there (10 gm)
• vs them: averages 0.0 over 2 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.