• 5.5 baseline — 0.6 × season 5.4 (5 gm) + 0.4 × last 10 5.7
• −0.1 opponent leak — they concede 152.1/game vs a 155.4 league average
• at this ground: too thin to count (2 gm) — shown, adds nothing
• vs them: averages 5.8 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.