Cooper Flagg tells Scott Van Pelt how he will be able to make an impact in the NBA next season. How much will the Mavs win in Flagg's rookie season and beyond with the current core of aging future Hall of Famers? play 1:50 What Cooper Flagg brings to the Dallas Mavericks Check out the best plays from Duke freshman Cooper Flagg as he is taken by the Dallas Mavericks with the No. -- Michael C. Wright0: 34.6%1: 46.2%2: 15.4%3: 0%4 or more: 3.8%How many NBA titles will Flagg win? The greatest player in franchise history spent 21 seasons in Dallas -- the most for any player with a single team in NBA history.