Baseball: Distance between two players

You can move the observer O. How does the distance from the runner R to the observer vary as the runner rounds the bases? You can set the speed of the runner. The fastest human runs about 41 ft/s as a top speed. A very fast base runner runs an impressive 23 ft/s average from home to first, and the slower 12-14. A fast typical runner sprints 17-20 ft/s. Why does the distance graph look the way it does for the umpire? Predict what it would look like for the pitcher or 3rd base player? How would the distance graph change if you took acceleration into account, or slowing around the bases?