From the Rules page;
Offensive Flow (how well the offense produces assists, avoids turnovers): point guard weighted very heavily, shooting guard weighted medium, small forward weighted medium.
Obviously the success of your team depends on other aspects of the game as well, such as the ability of your players to create opportunities for each other. The better offensive flow you have, the more high quality assisted shots you will get. Also, being able to rebound effectively will limit your opponents opportunities to score, and increase yours. Reducing turnovers and forcing turnovers is also important. The better handling you have, the better outside defense, and the more efficient you are at scoring (because the longer you take to score the more opportunities there are to turn it over) the better you will do in this department.
So basicly a good outside defense increases your OF as well. But I guess Passing and Handling are most important.
Please user the help forums next time.