Layer 1: Pitcher command profiles — K%, BB%, LOB%, expected ERA, ground ball rates, pitch arsenal data from Statcast. Not just traditional stats. The advanced metrics that tell you when a pitcher is better or worse than their surface numbers suggest.
Layer 2: Park factors — every MLB stadium has a measurably different effect on scoring. Coors Field inflates runs. Petco Park suppresses them. The model accounts for stadium-specific effects on the specific type of contact each pitcher induces.
Layer 3: Umpire zone analysis — each home plate umpire has a statistically distinct strike zone. Some zones expand, suppressing walks and scoring. Some zones compress, inflating them. The model factors in the specific umpire assigned to each game.
Layer 4: Platoon splits and lineup depth — left/right handedness matchups across the full batting order, lineup construction quality, and the times-through-order penalty that compounds after the second time through.
Layer 5: Velocity trends and bullpen fatigue — pitcher velocity decay over recent starts, workload management, and bullpen availability states that affect when relievers enter.
Layer 6: Environmental conditions — stadium-specific weather predictions for game time, including wind direction relative to ballpark orientation, temperature effects on ball carry, and precipitation modeling.