• 5.1 baseline — 0.6 × season 5.0 (20 gm) + 0.4 × last 10 5.2
• −0.5 opponent leak — they concede 141.4/game vs a 155.4 league average
• −0.8 at this ground — averages 4.3 there (46 gm)
• vs them: averages 4.7 over 3 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.