• 3.9 baseline — 0.6 × season 3.9 (18 gm) + 0.4 × last 10 3.8
• −0.5 opponent leak — they concede 80.8/game vs a 93.4 league average
• +0.4 at this ground — averages 4.2 there (59 gm)
• vs them: averages 4.5 over 6 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 15: 11 — far outside his usual range; kept in the average, not smoothed away.