Vertices for the eyes eyes

For modelling the eye with intention to get it to blink, some tutorials recommend to model equal no. of vertices top and bottom while others stress the importance of a middle vertice. Which is better?

For example, in your CGC classic, the model was done with a middle vertice: https://www.youtube.com/watch?v=4gw3wliQVTY as compared to equal no. in this tutorial