When you are playing a GB match and you are confused of which team you should go on you look at the scoreboard to see what the other team have done which results in you picking the correct team.
Player 1 : I thought you were going to pick the wrongteam there.
Player 2 : Naa, I did a Mike.
In a given situation, "pulling a Mike" is when you assess and evaluate all options, figure out the best possible course of action, and then proceed to do the exact opposite. In short, this is to make the most dumbfoundly awful decision that one can make at any given point. A "Mike's" natural habitat is in any matter involving women, sex, copious amounts of alcohol, or some awkward combination of all three. Nearly always, disappointment ensues.
Phil: Man, did you hear about Mike pulling a Mike the other day at my place?
Noah: Yeah, didn't he drink himself into a stupor and projectile vomit all over your room or something?
Phil: He did, and he was also somehow butt-ass naked too. And that's terrible.