While I don't understand my team mates a lot of time and get heated occasionally, I try to be indifferent and realize I can only do so much. The mentality you have to get in is adapting your play style around your team mates. If they are doing something stupid, figure out how you can exploit that. Find the cracks and patch them on your team. Find the cracks and widen them on their team. That's the secret to winning in this game, figuring out what everyone is doing and adapting to it, there is not a single strategy that you can adapt to, it is fluid every game.
Sometimes you'll be shaking your head wondering how you team threw it, other times laughing uproariously at how you pulled out a win.