• 13.1 baseline — 0.6 × season 13.8 (20 gm) + 0.4 × last 10 12.1
• −0.3 opponent leak — they concede 209.2/game vs a 213.6 league average
• +0.4 at this ground — averages 13.5 there (86 gm)
• vs them: averages 12.4 over 13 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. Round 7: 26 — far outside his usual range; kept in the average, not smoothed away.