Cooper Flagg and the Dallas Mavericks hosted the defending champions OKC Thunder at the American Airlines Center on Monday night. Flagg is coming off his best performance of the season so far in the Mavericks' 139-129 win over the Toronto Raptors on Sunday.The No.1 pick of the 2025 NBA draft is also playing in the first back-to-back games of his career. It's something that he needs to get used to, with the Mavericks resting several players to help them recover from minor injuries.Flagg started the game at point guard once again, alongside Max Christie in the backcourt. The Mavs continued to experiment with their prized prospect, but it hasn't pan out. He's averaging 3.3 assists in his first three games and committing 2.7 turnovers per game.So how did Flagg perform against the Thunder?Here are Cooper Flagg's stats for the game:PlayersPTSREBASTSTLBLKTOPFMINFG3PTFT+/-Cooper Flagg220200031:081-100-40-0-20What happened to Cooper Flagg?In his first back-to-back game of the season, Cooper Flagg didn't look like himself. He was struggling with his shot and didn't have the same bounce he had on Sunday against the Toronto Raptors.Flagg also ran into the great defense of the OKC Thunder, who were missing two of their best defenders in Jalen Williams and Alex Caruso. He continued playing as the point guard, but he didn't register an assist for the second time in four games. Nevertheless, the Dallas Mavericks didn't put Flagg in a position to succeed. He's not a natural playmaker and could have been better playing as small forward. He got his first taste of how good the defending NBA champions are, which should help him in the long run. The Mavericks and Thunder are in the same division, so Flagg has three more chances to show his stuff against Shai Gilgeous-Alexader and the rest of the defending champions. Bill Simmons calls out Jason Kidd for playing Cooper Flagg as point guardWhile Jason Kidd remained adamant that letting Cooper Flagg play point guard is what's best for his development, The Ringer's Bill Simmons called out the Dallas Mavericks coach on a recent episode of his podcast. "I wanna go on the record really emphatically," Simmons said, according to The Smoking Cuban. "This 'Flagg playing point guard thing is f*cking stupid. It's stupid. Stop, Jason Kidd… We know you lucked out with the lottery… But this is not the right way to bring in a kid who’s not even 19, and who doesn’t know what kinda basketball player he is yet, but he clearly is special. You’re putting all this extra stuff on him that I think is ridiculous."Following another dud as the primary point guard, it will be interesting to see if Kidd sticks to the plans, especially with the team at 1-3 already.