Microtubules are polymers that play many important structural and functional roles within biological cells, including the separation of newly replicated chromosomes into the daughter cells during cell division. In order to catch the chromosomes that they must transport, microtubules grow out of the centrosome in each of the daughter cells. For any particular microtubule, epochs of steady growth are punctuated by episodes of rapid decay; this is known as dynamic instability. It allows for multiple attempts on the part of each microtubule to hit the small target at the center of each chromosome known as the kinetochore, where the microtubule can attach and apply traction to the chromosome. The optimal design of dynamic instability is the subject of this paper.