2018 NBA Draft Prospect Report Part 5: Jaren Jackson Jr.

Defensive impact

Jaren Jackson Jr. does not possess Mohamed Bamba’s ridiculous physical measurables. But he has a comparable effect on the game.

Where Bamba uses his sheer size to deter shots outside the effective radius of a normal big man, Jackson uses his quickness and instincts. His ability to cover ground in help defense without conceding too much to his primary coverages is particularly important as he was often forced to play power forward at Michigan State. Thus the defense drew him out to guard on the perimeter more than he would in the NBA.

On the play above, Jackson digs down from his primary assignment on the perimeter to block a shot under the basket. Notice how he does not fully commit to helping off his man until the driver commits to his dribble, takes a path that cuts off any reasonable pass-out angles and times the block perfectly.

Jackson’s ability to make lemonade out of lemons – racking up elite rim protection stats while frequently guarding opposing perimeter players – contrasts starkly with Arizona Wildcats big man Deandre Ayton’s defensive performance.

Ayton’s abysmal showing in the NCAA Tournament and poor defense overall has sometimes been excused as a product of him being forced to play out of position. There may be something to that.

But Jackson was also forced out of his natural role. Only one of the two looked completely helpless when forced to make decisions on defense.

Another contrast between Ayton and Jackson is the Jackson’s absurd motor. On a regular basis he battles through screens, makes multiple efforts and stays engaged both mentally and physically.

Here, Jackson is again guarding a perimeter player, this time on a baseline out-of-bounds play. He fights through a screen and manages to block his man’s jumper.

After an ugly-looking floater attempt after a nice spin move attacking a closeout, he chases Indiana Hoosiers’ Zach McRoberts 94 feet for a highlight reel block. Rather than stewing about the previous play’s result, he keeps his head down and stays in the play.

This is the kind of effort level Jackson brings on a night-to-night basis.

Here, he switches onto Juwan Morgan in the post and shows why he is such a fearsome interior defender despite his underwhelming size. He gets off the ground quickly, does not bite on multiple pump fakes and registers two blocks before tipping the rebound out.

In the NBA, many teams try to take elite traditional rim protectors out of the game by forcing them to switch onto shooters and guard them in the corners, drastically increasing the amount of ground they have to cover to make plays at the basket.

Jackson has the mobility to get over and make weakside rotations even if his man spaces all the way out.

His excellent timing, quickness off the ground and aggressive help instincts combined with his motor, awareness, quick-twitch mobility and top-end speed make him both a versatile man-to-man defender that can hold his own switching onto guards and an omnipresent help defender that offenses simply cannot scheme around.