Since we have so many first-season players in this league...I found this section of the manual to be the most helpful part of building a good team. It basically tells you how each possession is decided. Certain players only need certain skills (at least to win at THIS level), so make sure you're training/buying the right skills!
Match Ratings
Each player that has played more than five minutes in a given match receives a rating, with 1 being the lowest. This rating is based on a combination of your player's stats and his overall contribution to the team effort. Note that this has nothing to do with the player's overall skill; if your worst player overall is the best on the court, he'll have the highest rating!
Your team also receives several ratings per match. These team ratings are used in the calculation of what happens each possession. Here is a synopsis:
Outside Scoring, Defense: Both guards weighted heavily, small forward medium, power forward slightly.
Inside Scoring, Defense: Center weighted heavily, power forward somewhat heavily, small forward medium.
Rebounding: Center and power forward weighted heavily, small forward somewhat heavily, both guards medium.
Offensive Flow (how well the offense produces assists, avoids turnovers): point guard weighted very heavily, shooting guard weighted medium, small forward weighted medium.