In Starcraft 2, how are optimal builds discovered? Is it really just trial and error and/or hand timing?
I'd love to know what mathematical algorithms could be used to discover the optimal timings.
For example: Use an equation to know empirically what is the earliest possible time 15 unit(s) X's could be produced, or 10 unit X's and 3 unit Y's and 3 unit J's.
Edit: I've changed my description from "good" builds to "optimal" builds to narrow the scope.