EPTSince Season 2 started I've been at the top of Platinum in both 3v3 and 4v4 and hovering in this area. I find though that is difficult to get consistent wins and advance because I'll be dragged down by teammates whose mechanics are no more than Silver League (1s) in quality.
While I do all I can to help these people out it is very difficult to succeed when you have teammates who make fundamental mistakes like not making an Orbital Command before 20 food, not Chrono boosting, or not researching Warp Gates (and the various kinds of Zerg bad that is possible). Compound this kind of play with poorly executed rushes and rush defenses and you get games that are just not fun.
I wonder if Blizzard should take a person's overall ratings in other types of play (like 1s) into account when matchmaking for team games. The games that I win are only when people I am matched with are equal to or better than I am. I'm not saying that I am infallible, just the opposite; I'm saying that it is very difficult for me to pull up the play of grossly bad teammates. It would be nice ever everyone in the game was at my level or better, on both sides. All rushing aside, the play would be much more satisfying. I'd rather lose knowing I was BESTED instead of LET DOWN.
There is nothing worse than hearing a teammate say he is going Colossus, then looking over at his base at 14 minutes, and seeing NO Colossus, NO WARP GATES, and a Nexus with full energy not making Probes.
