Most of the teams I ever see win are agressive teams. I don't me be crazy or go on a suicide mission. Another very important aspect of the game is communication with your other team members. The only way you can win is with very good communication skills. You always have to tell your fellow team mates were you are, what your doing, and who you killed.
Communication is very important and a skill that is hard to develope.
Other sucsess comes to teams who are able to sneek behind the enemys lines. Infultration can be devistating to an oposing team. To do this you usualy have to go up the left or right side of the field. Only the best teams can master this technique. Remember when you go up one of the sides of the field don't bring your whole team bring two people who are fast,quiet, and have good aime.