what mega said is very true. that's why i made a few guidelines on how to make sure u win every game you play
1) call a lane and if you don't get it, go afk.
2) if the enemy team gets first blood, call your team noobs and afk.
3) if someone calls you a noob, rage at them, then afk.
if u follow these steps, you will only have wins and leaves, and most importantly... zero losses.