On Wednesday, Charli Collier and Natasha Mack, two probable first round picks in the upcoming WNBA draft, should both declare, faced off. In my draft board for the 2021 draft, I put Mack above Collier, with Mack 2 and Collier 3. I am an outlier in this, with a more typical board looking like this one from Ben Dull of Winsidr, who has Collier 2 and Mack 10. The main reason I am higher on Mack than Collier is the defensive potential of Mack, coupled with concerns about Collier’s defense.
One way of looking at a player’s defensive potential for the next level is looking at their steal and block rates. While in the WNBA, block rate is not a particularly good measure of defense, it is a useful indicator at the college level of a player’s athleticism, necessary for success at the next level.
Steals are a valuable indicator, particularly for players who gets them without gambling unnecessarily. Combined in the stocks column, they give a good indication of a player’s potential on defense. Here are Mack and Collier’s numbers, with some current WNBA centers’ senior season stats included for comparison.
I included a cross section of WNBA centers, of varying levels. Sanders, Howard, and Jonquel Jones have all shown themselves good enough to play center on championship level defenses. Bri Jones played well in 2020, though long term is likely a good backup center, and Coates, the 2nd pick in the 2017 draft, will be lucky to be in the league this upcoming season.
Mack has the highest stocks combination, with an absurd 6. Collier has the lowest at 1.6, by a decent margin. For all of Collier’s gifts as an offensive player to matter, she needs to be able to stay on the floor on the defensive end.
Mack does not just block shots by dint of being really tall, a la Brittney Griner. Mack is not particularly tall for a center at 6’4” and quite a few of her blocks are on opposing players shooting jump shots, and flying in as a help defender.
This play against Texas is a good example of Mack’s athleticism and ability to help as a defender. This is common for Oklahoma State, where they have Mack guard both forwards, trusting her to be able to guard both with her speed and instincts.
Mack’s defensive technique needs refinement, but it is impressive how effective she is now. A WNBA team may need to demonstrate some patience with her, but she has the potential to be a defensive player of the year caliber defender in time.
In contrast, the downside risk with Collier is that she simply will not be able to hang in the WNBA defensively, much less become a positive presence as one would expect from a top 2 pick. Collier has a lot of work to do to not share the fate of Alaina Coates and Teaira McCowan, two other high draft picks who have had their WNBA careers stalled because of their defensive limitations.
Collier’s relatively few blocks tend to come when an opposing player drives directly at her. Collier struggles when guarding on the perimeter, or in defending screens. This play shows the struggles Collier has guarding on the perimeter. Taylen Collins beats Collier off the dribble, and while Collins has a bright future, she is a freshman still figuring out college basketball.
Young bigs who make it to the WNBA typically struggle on defense, and even the best take time to learn the game. In particular, defending in space on the pick and roll is something that is among the biggest changes from college to the pros. A WNBA big has far more responsibilities in defending in the pick and roll, and far less opportunity to post up, than they do in college.
The demands that bigs be able to guard in space increase each year as well, as more teams play with 4 or even 5 shooters at a time, with guards who are comfortable shooting off the dribble. The lack of spacing in a WNBA game from 2015 is jarring with the lack of spacing. It’s important for WNBA teams to consider what a center in 2025 might be expected to be able to do to stay on the court.
Charli Collier is a talented, hard working player, but a WNBA team that drafts her needs to be confident they are not getting an Alaina Coates who can occasionally shoot 3s. Even in a weak draft, there are other choices. Natasha Mack has been able to put up incredible numbers, even without much high level experience. With continued coaching, and her own drive to succeed, Mack’s ceiling is sky high.