The game engine computes the quality of your best 14 players in the team, not by the stars. For example, you have 5 players with quality of 15, other 5 players with quality of 25, and the remaining 4 with quality of 35, then your average team quality would be 24.3.Then you will likely to put into a league with teams of quality ranging from 20.x to 34.x. If your team quality is 25.x you may face team with quality level of up to 40.