SC2 Build Order Tester Algorithm

Sup /prog/,

/v/ here, I'm a hobby programmer who's currently attempting to write a build order optimizer for SC2 [both for the fun of programming and so I can play SC2 better by having some sick build orders].

I'm having a bit of trouble trying to figure out what search algorithm I should be using to evaluate which build order is best in an efficient time. The major problem is that I have a large number of nodes [the state of the game each time I could make a decision, including 'wait'], each node has a large number of edges [each decision I could make] and the only real way to compare the build orders is at the end [the decision trees cannot be directly compared except when taken as a whole, rather than comparing nodes of n+1].

>>1
What you are looking is a heuristic.  A heuristic is a function that allows you to compare different states when you don't have enough information available to make an unbiased comparison.  (Certain search algorithms find optimal solutions with the right heuristics, such as A*, but the search space here is too big so we are going to ignore that possibility.)  Read up on how to choose a heuristic.

Recommended reading: http://www.amazon.com/Paradigms-Artificial-Intelligence-Programming-Studies/dp/1558601910

>>1
Just look at http://code.google.com/p/evolutionchamber/ for inspiration.

>>2
but the search space here is too big so we are going to ignore that possibility
You don't actually understand heuristics.