• 20.1 baseline — his last 10 games; only 2 this season, too few to blend
• −0.1 opponent leak — they concede 367.1/game vs a 369 league average
• −0.6 at this ground — averages 19.5 there (4 gm)
• vs them: averages 21.2 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.