Play-level splits, opponent-adjusted ratings and availability tracking, each with the sample size behind it.
Ratings, tendencies and matchups. Offense and defense are solved together, not one against the other's raw baseline.
How a team plays with a player on the field — split play by play, so a game he left at halftime counts on both sides.
Who is actually going to be out there. Practice reports, reserve lists and a model for the ones listed questionable.
Season and weekly points in the format you play, the routes and targets behind them, and two players side by side.
Stadium forecast for the hours around every game — wind and rain hour by hour, flagged when it turns, refreshed hourly.