Welcome to our offseason series “Immediate Impacts.” Most rookies don’t provide positive value to their teams right out of the gate. But as we saw last season with guys like Jalen Williams, Walker Kessler and Keegan Murray, some rookies can help their teams from Day 1. Over the next few months, we’ll break down ways that members of this incoming class can have that very impact. 

Last season, late first-round pick Walker Kessler established himself as one of the premier defensive bigs right out of the gate.

And while rookie center Dereck Lively II is two years younger than Kessler was during his rookie run, if he could put together a similar inaugural campaign, it could change the trajectory of the Dallas Mavericks. And, by extension, alter the entire Western Conference landscape. 

How is it that this raw 19-year-old big man can have such an immediate impact? Let’s find out.

Although our story’s hook centered around defense, let’s get the obvious offensive contributions he could provide out of the way. Lively is a big who likes to roll to the rim and finish. And one of his new teammates on the Mavericks is Luka Doncic, who, among other things, is one of the preeminent lob passers in the association. 

In his lone season at Duke, Lively completed 70.0% of his shots at the rim (5 feet and in) and 68.8% of his close 2s (10 feet and in), per AutoStats data. He isn’t the best screener yet, but he’s adept at slipping these actions when the defense sends two defenders at the ball.

Like this:

Being that Doncic is who he is (one of the very best offensive players on the planet), NBA teams often trap/blitz pick-and-rolls where he is the ball handler, meaning that Lively will be able to pick up where he left off as a roller in college. 

But the team already has Dwight Powell to punctuate Doncic’s lobs? How does Lively doing what Powell already does constitute making an immediate impact?

That’s where the defense part comes in.

On the surface, Powell’s defensive DRIP (our in-house catch-all defensive metric) of plus-0.4 may seem pretty solid, especially when you compare it to someone who is getting ready to enter their rookie season (rookies typically aren’t that good at defense). However, last season there were 45 “bigs” (power forwards/centers) who ranked higher in our metric than Powell (minimum 500 minutes played).

That means that he’s far from a good/elite defender, and considering how important his position is, that’s not a good sign as it pertains to your defense.

Frankly, outside of Maxi Kleber (who spent most of the season battling injury), no bigs on the Mavericks’ roster were really holding down the fort on that end of the court – hence why they finished the season 25th in our adjusted defensive ratings.

Adjusted Defensive Ratings

(Sidebar: to further compound the situation, the Mavericks finished 22nd in opponent points in the paint per 100 possessions.) 

As we said, it’s rare that a rookie comes into the league ready to be a positive defender. But if someone is going to do it, it may as well be Lively. We’ve talked about this before, but rim protection is the most influential factor that contributes to a team’s defensive rating.

And our friend Lively has all the makings of someone who can be a great rim protector in this league. He’s got great length (measuring in at 7-foot-1), stays near the paint, has strong threat detection sensors (a cool way of saying court awareness)/reaction speed, and can get vertical quickly.

The great rim/paint protectors are also able to deter would-be penetrators from hunting in their territory altogether. And if Lively’s college tape is any indication, that is something that Dallas will be able to look forward to during his professional career. 

Lively led the Atlantic Coast Conference (ACC) by blocking at least one shot in 20 games (two more than second-place Jesse Edwards of Syracuse). This does come with a tradeoff of increased fouling (second-highest foul rate in the ACC), but we have some promising data on that front coming up later.

But Lively isn’t strictly an interior guardian. He actually covers ground pretty well for his size. He’s able to defend in transition or switch onto and contain smaller adversaries. 

With all this said, I think it’s less likely that Lively is a legit contributor as a rookie than someone older and more polished like Brandin Podziemski. As it stands, he’s still pretty frail and learning defensive discipline and how to properly use his body. Plus, he plays the most important defensive position on the floor, so his responsibilities will be laborious from the get-go. 

But there is a reason why he warrants a spot in our series. As Swish Theory Draft Analyst Chip Jones said on a recent episode of the Thinking Basketball podcast, few players in the nation improved as significantly through the course of the 2022-23 season as Lively. 

For instance, look at how much he improved his pick-and-roll defense in just a few months. In the first clip below (from a game on Nov. 30), he looks stiff and off-balance as he’s struggling to defend the action. So much so that he quite literally trips himself up. In the second clip (from a game on Feb. 6), he does a nice job shuffling his feet, using his hands to bother the driver, and recovering back to his man. 

Now, here’s your reward for staying with us. You can also see his in-season growth when you look at his foul rates.

For the entire season, he may have had a foul rate of 6.9 fouls committed per 40 minutes. But when you look at his progression in this area on a month-to-month basis, you see a promising trend taking place.

Dereck Lively Fouls Per 40

As the season went on and his institutional knowledge increased, Lively was fouling less and less. And it’s this display of rapid growth that makes me optimistic that he may be able to get to NBA speed fairly quickly. He doesn’t need to match Kessler’s opening performance down to the letter. But if he can make an impact defensively, it could change the team’s ceiling in 2023-24. 

Just imagine how dangerous a Dallas team with Doncic, Kyrie Irving, and a respectable defense could be – particularly in a Western Conference that’s full of teams with uncertainty surrounding them. 

When you really think about it, there’s a world where everything clicks for the Mavericks this year, and they run through the gauntlet in the West. And if that happens, and Lively has anything to do with it, that would make him more than worthy of his inclusion in this series. 

If you enjoyed this article, be sure to check out the first installment of “Immediate Impacts” on Jordan Hawkins, and our second one on Brandin Podziemski.