Grading Cooper Flagg's 2025 NBA Preseason Debut with Dallas Mavericks

Cooper Flagg made his first appearance in a (non-summer league) NBA jersey on Monday, when his Dallas Mavericks annihilated the shorthanded Oklahoma City Thunder, 106-89.

Individually, Flagg may have been a little deferential to start, but by the end of his 14 minutes of action, he'd shown just about everything that made him the No. 1 pick in June and put up 10 points, six rebounds, three assists and a block.

Now that his impressive debut is in the rearview, it's time to bust out the rubric and give him some traditional letter grades.

Playmaking: A

Richard Rodriguez/NBAE via Getty Images

Early on, it felt like Flagg was actually overpassing a bit. On a couple of catches, he was open enough to shoot or attack a closeout, but he quickly swung the ball instead.

That's not necessarily a bad thing. He is on a team with plenty of veterans. Establishing himself as a ball-mover should make it easier for him to ingratiate himself.

The more encouraging passes were the ones that went down as assists.

On one, Flagg dribbled the length of the floor against pressure defense from Cason Wallace (one of last season's better perimeter defenders), drew two defenders in the lane, seemingly went up for a shot and then dropped an overhead pass to a wide-open finisher.

On another possession, he drove a closeout, drew two again and dropped an underhanded dime to Dereck Lively II. And on his third and final assist, he showed patience at the top of the key, waited for P.J. Washington to get open on a cut and found him for an and-one.

The last one was a little more run-of-the-mill than the first two, but on balance, Flagg showed the potential to be a plus playmaker, especially relative to other forwards.

Defense and Rebounding: A

Zach Beeker/NBAE via Getty Images

Flagg's first big highlight of the night came on the defensive end and within the first few minutes of the game.

Isaiah Joe beat D'Angelo Russell on a cut around Jaylin Williams at the top of the floor, caught the ball in the paint and looked like he'd have a freebie at the hoop.

But Flagg exploded from the opposite side of the paint and swatted the ball off the glass. His effort led to a fastbreak bucket on the other end.

Nothing else he did on that end was quite as awe-inspiring, but he did do a good job of contesting multiple shots from OKC's perimeter players.

And perhaps his steadiest contribution throughout the night was the way he ended defensive possessions as a rebounder.

The 18-year-old didn't collect a ton of contested boards against bigs, but he read the bounces well and showed consistent effort whenever shots went up.

Had Flagg played a normal, regular-season minutes load, he almost certainly would have had a double-double.

Scoring: B+

Stacy Revere/Getty Images

This grade probably feels a little nitpicky. Ten points on 3-of-6 shooting (including 2-of-3 from deep) in 14 minutes is obviously good.

And Flagg had a pair of impressive buckets that showed both his agility and athleticism around bigs inside and his upside as a pull-shooter from three.

But the Duke product may need to learn that a little more aggression as a scorer might actually be the unselfish approach for him to take.

Especially while Kyrie Irving is out, Flagg creating or taking shots for himself will often be Dallas' best source of offense. Passing out of good scoring opportunities hurts his team.

Eventually, he'll find the right balance between being a finisher and a distributor.

Overall: A

Richard Rodriguez/NBAE via Getty Images

Preseason action can always be taken with a grain of salt, but again, Flagg's debut was a vivid reminder of why he went first overall.

He's so much more than the highlight-reel dunks and blocks from his high school mixtapes. Those are fun, but what could really make him special is his feel for the game, his willingness to defend and his burgeoning shooting ability.

Whether it's fair or not, being drafted on the heels of the still-ludicrous Luka Dončić trade means Flagg will draw comparisons to the all-timer. And it may be impossible to live up to those.

But after his freshman season at Duke, a couple summer league games and now one preseason contest, it's getting easier to imagine a world in which Flagg develops into 80-85 percent of the offensive engine Dončić was, while also being a Defensive Player of the Year candidate.