Covering Circle Radius versus Extreme Spread
The figure below illustrates the difference between the Covering Circle Radius and the Extreme Spread measurements. Given that AB is the extreme spread measure, a back circle which has AB as a diameter has been drawn. At points A and B, red circles have been drawn with a radius of AB.
Thus points in the green region are:
- Outside circle that has AB as a diameter
- Closer to A than B
- Closer to B than A
So if a shot happens to fall in the green region, then the covering circle radius will have to be more than 1/2 of the ES.