I cannot stress this enough: the best players in Starcraft can change their strategies in a heartbeat. My friend and I were playing games, and although he is good at managing his units to build expansions, harvest minerals and vespene, etc., I still had the upper hand. Why? He continually used the same strategies, while I was able to shift quickly when it wasn't working. Okay, so my Mutalisks are getting slaughtered by his Photons? Guardians. Okay, so their Bunker is repelling my 'Lings? Lurkers. My friend learned a valuable lesson from the games we played.

A player who uses the same strategy 5 times may get caught the sixth time with his pants down, attempting to combat a strategy streamlined to smash his. At this points, the player with the predictable strategy will either shift gears or will die because he couldn't.