Pitchers PlanetYour pitch. Its potential.
Stuff+ calculator
Measure pitch quality and explore better locations. No CSV or account needed.
Have an entire session?
Upload CSV or Excel for player reports, pitch charts, and location heatmaps.
Understand the number
What is Stuff+?
Stuff+ is a model-based measure of a pitch’s physical characteristics. In this calculator, velocity, movement, spin, release, extension, pitch type, throwing hand, and differences from the pitcher’s fastball feed a trained pitch-value model.
It evaluates the measured pitch profile rather than simply counting strikeouts or averaging velocity. Two pitches at the same speed can receive different scores.
Read the Stuff+ methodology →Stuff+ vs. Pitching+
| Model | What it evaluates | How to use it |
|---|---|---|
| Stuff+ | Pitch shape and release, without plate location | Compare pitch profiles and track changes within this model. |
| Pitching+ | Pitch characteristics plus horizontal and vertical plate location | See how the model evaluates where a pitch was thrown. |
These are Pitchers Planet’s deployed Trackman Analyzer models. Scores are not interchangeable with FanGraphs, MLB team models, or other Stuff+ providers. Our models do not include count or batter handedness.
Calculator questions
Before you calculate.
Is the Stuff+ calculator free?
Yes. You can upload data, calculate scores, and export reports without creating an account or paying. Your session starts empty; no example file is loaded automatically.
Can I calculate Stuff+ from velocity and spin rate alone?
Not with this model. It also needs movement, release height and side, extension, pitch type, throwing hand, and a fastball baseline. It does not invent missing measurements. See the data guide for exact field names and units.
What is a good Stuff+ score?
Above 100 is above this model’s saved reference; below 100 is below it. Consider pitch type, sample size, and the number of pitches actually scored. A high number is not a guarantee of game performance, and this reference is not automatically an MLB average.
Can I type in one pitch manually?
Yes. Enter pitch type, throwing hand, velocity, movement, spin, extension, and release measurements in the form above. Add your fastball reference. Location heatmaps evaluate your pitch across the zone and suggest targets. No CSV is required.
Why is my Stuff+ or Pitching+ score blank?
A pitch may be missing a shape or release measurement, a recognized pitch type, throwing hand, or the pitcher’s fastball baseline. Missing plate location prevents Pitching+ but can still allow Stuff+. The troubleshooting guide explains what to check.
Can I compare scores across sessions?
Yes, with care. The saved scoring scale stays fixed, but manual scores use the fastball reference you enter; uploaded reports calculate it from your selected sessions. Keep session selection, pitch tagging, measurement quality, and model version consistent when comparing results.