A 19 year-old should not impact an NBA game as much as Cooper Flagg did last night. He finished the game with 26 points, 10 rebounds (4 offensive), 8 assists, 3 steals, and 1 block. He was a plus-3, the only starter to have a positive plus-minus. He has made everyone rethink how impactful a rookie can be. Typically, even "good" rookies come with the disclaimer that they're good for rookies.
Flagg is a good NBA player, full stop. That's not the issue with the Mavericks right now. In fact it's the players around him aren't impacting winning as much as they should be.