Documentation

Gradient Start Location

Determines the starting point for the gradient.
If set to 0, the gradient will start from the center of the pie chart. If set to 100, the gradient starting point will coincide with its end point. 
The default value is 80, which provides a subtle sense of depth.

This setting is available if the Pie Chart on Nodes toggle is enabled, and the selected Fill Mode is “Gradient to a derived color” or “Gradient to a single color”.