• 90.6 baseline — 0.6 × season 88.9 (18 gm) + 0.4 × last 10 93.0
• −5.9 opponent leak — they concede 1576.6/game vs a 1686.6 league average
• −57.4 at this ground — averages 33.2 there (5 gm)
• vs them: averages 50.0 over 5 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.