• 1.3 baseline — his last 4 games; only 1 this season, too few to blend
• +0.4 opponent leak — they concede 16.6/game vs a 12.3 league average
• vs them: averages 2.0 over 1 game — 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.