Tired of calling positions and arguing about pick order? Team Builder is here to solve your League of Legends team composition woes.
Team Builder allows players to select what champion, map position, and role they are interested in playing on a team. The system then attempts to match players with like-minded teammates. The system was briefly tested in beta and proved to be so popular that it has now taken up permanent residence on the Fields of Justice. Team Builder is an entirely separate queue from normal Blind Pick and Draft Pick to preserve balance in the other game modes. However, Riot Games has decided that Team Builder will not be available in ranked until they can figure out how champion banning could be effectively implemented.
Wait times for queues are estimated to be relatively stable regardless of champion or role selection. However, since Team Builder is just being implemented, the estimated wait times will frequently be inaccurate. As the mode is used more and collects more data, it will be able to give more accurate predictions.
For more detailed information, you can check out this FAQ section.