Nats Stats Pro · Pitch Design
Pitch Lab
A physics-based pitch simulator from the pitcher's point of view. Dial in velocity, spin, tilt, and release like a Rapsodo session — the flight path comes from real aerodynamics (drag + Magnus), not canned animations.
4-Seam Fastball 94 mph · 2300 rpm · 1:00
Strike
Batter:
Release
94.0mph
eff. 94.4 mph
At Plate
86.2mph
0.401 s flight
Ind. V Break
+18.3in
total drop -12.0 in
H Break
+10.5in
arm side
Spin
2300rpm
active 2139 rpm (93%)
Tilt / Gyro
1:00
gyro 22°
VAA
-4.9°
vertical approach
HAA
-1.0°
horizontal approach
Release Angle
-2.6°
horiz -2.9°
Plate Loc
+0.00, 2.50ft
in the zone
Extension
6.3ft
release 54.2 ft out
Air Density
1.198kg/m³
70°F · 50 ft
The Pitch
Pitcher
Velocity94.0 mph
Spin Rate2300 rpm
Spin Efficiency93%
Tilt 1:00
Aim +0.00 ft, 2.50 ft
Release Point
Release Height5.90 ft
Release Side (arm side)1.80 ft
Extension6.3 ft
Movement Profile
Conditions & Advanced
Temperature70 °F
Altitude50 ft
Drag Coefficient0.33
Zone Top3.40 ft
Zone Bottom1.55 ft
Reading the Numbers
Velocity. Speed of the ball out of the hand. Air drag removes roughly 8–10% before the plate.
Spin rate. Total RPM on the ball. Only the transverse (non-gyro) part creates movement.
Spin efficiency. Share of spin that is transverse and produces Magnus force. A gyro slider can be under 30%.
Tilt. Spin direction as a clock face from the pitcher's view: 12:00 rides, 6:00 drops, 3:00 runs to the pitcher's right.
IVB. Induced vertical break — how far the pitch deviates vertically from an identical spinless pitch.
HB. Horizontal break versus the same spinless reference, positive toward the pitcher's arm side here for a RHP.
VAA. Vertical approach angle at the plate. Flatter (closer to 0°) plays up at the top of the zone.
Gyro angle. Angle between the spin axis and the transverse plane. 0° is pure movement spin, 90° is a football spiral.
The model integrates gravity, quadratic air drag, and Magnus lift (Alan Nathan's lift-coefficient parameterization) with an RK4 solver at 1 ms steps. Release angles are solved automatically so the pitch crosses the front of the plate at your aim point — just like a pitcher adjusting to hit the mitt.