A donut chart of your spin signature
The Spin Distribution card shows what percentage of your classified shots rolled up (topspin), went through (flat), or cut under (slice). In our 77-shot demo: 89% topspin, 9% flat, 1% slice.
89%
Topspin
9%
Flat
1%
Slice
How is spin estimated?
At the moment of impact, CourtsidePlay looks at two signals on the gyroscope: the direction of wrist rotation (up-over-the-ball versus under-the-ball versus neutral-through-the-ball) and its magnitude relative to the swing speed. These two numbers map to topspin, slice, or flat with useful accuracy — especially on groundstrokes.
- Not a direct measurement of spin RPM — it's a shape estimate from wrist motion.
- Most useful for tracking trends across many matches (e.g. slice rate going up under pressure).
- Only classified shots count; serves are excluded from the distribution since they're overhead impacts.
