According to the implementation details of the gameplying AI, EISbot, the software was implemented as a Goal-driven autonomy architecture which is using the behavior language ABL. Different modules for production, spatial planning and economy are generating behavior trees on the fly which allows the AI software to win every game, especially against a human player.
The only problem is, that it's hard or even impossible to win against the EISbot system. It was designed with the purpose to beat easily the counterpart and their main advantage over a human player is, that it can play 24/7 without any mistake. What is the best strategy to win against a AI which is superior?
 Weber, Ben George, Michael Mateas, and Arnav Jhala. "Applying goal-driven autonomy to starcraft." Sixth Artificial Intelligence and Interactive Digital Entertainment Conference. 2010.