• 1.3 baseline — his last 6 games; only 1 this season, too few to blend
• −0.1 opponent leak — they concede 88/game vs a 93.4 league average
• −0.1 at this ground — averages 1.3 there (4 gm)

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.