• 1.9 baseline — 0.6 × season 2.2 (20 gm) + 0.4 × last 10 1.4
• +0.3 opponent leak — they concede 64.3/game vs a 56.6 league average
• +0.5 at this ground — averages 2.4 there (70 gm)
• vs them: averages 3.1 over 10 games — evidence, never summed

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 2: 11 — far outside his usual range; kept in the average, not smoothed away.