Unlike circles, which all have the same shape, ellipses can be one of an infinite number of shapes. You can make them long and thin, like a surf board, or almost circular, like, um, a circle.
Ellipses are classified according to their ECCENTRICITY, which is a measure of how far they are from being a circle. Eccentricity is calculated by dividing the distance between the focus points by the distance of the longest, or major axis. The further apart the focus points, the higher the eccentricity is. The closer the focus points, the smaller it is.
The eccentricity of an ellipse will be between 0 and 1.
I chose an eccentricity of 3/7, or 0.43, for LOOP. I didn't want to go higher than that since the table becomes too narrow, and I didn't want to go lower, since you can't clearly see the elliptical shape.