Josh Jackson isn’t the best perimeter defender in the draft. He’s a good one, and deserves much of the recognition that he has garnered, but there have been two standout defenders head and shoulders above him.
The first is obviously OG (pronounced “Ogg”) Anunoby. Anunoby’s impressive tournament performance locking down Jamal Murray put him on draftniks’ radars, and his tree trunk legs, elite mobility, and excellent length make him a surefire lockdown defender.
But Jonathan Isaac has, very quietly, proven himself to be perhaps the most intriguing defensive prospects to come into the NBA since Aaron Gordon. At 6’11 and with a 7’1 wingspan, his physical tools are compelling in and of themselves. But both his production and manner of production have been unique among perimeter prospects this decade, and he has a chance to grow into a perennial All-Defense candidate from the 4 position.
The first thing that jumps out is just how much ground Isaac is able to cover. With his long strides and long arms, he can stunt at a player off-ball and recover with ease to his man, or hedge hard around the top of a pick and roll and return to his cover before the opposing point guard can make any sort of read.
His dig on Kennard disrupts what was otherwise a routine drive. He then recovers effortlessly to Tatum, remains under control, and forces up a very tough end-of-clock over a high contest.
Here, too, he closes out under control after an aggressive help into the paint, easily slides in front of an NBA-caliber athlete, and then uses his length and quick hands to poke the ball free for a steal.
Isaac’s intuition as an off-ball defender and incredible speed to recover back to his man make him an incredibly valuable defensive player. Florida State trotted out two centers taller than 7’1, but Isaac was inarguably the most impactful defender on the team.
His defensive stats support this too, whether it’s the frequency with which he created defensive events, his outstanding rebounding, or the derivative DBPM. Isaac was an elite freshman in each of these categories.
With a steal rate of 2.4% and a block rate of 6.2%, Isaac has one of the highest event creation of any wing since 2010, when Sports-Reference introduced per possession statistics into their database. Only OG Anunoby’s freshman year (in which he only played half of the minutes Isaac did this year) and KJ McDaniels’ junior year surpass Isaac’s number among prominent, drafted wings. Isaac’s DBPM of 6.2 is also the third best since 2011 for a drafted freshman wing, behind only Mikal Bridges (6.3) and Rondae Hollis-Jefferson (7.2).
The most interesting part of Isaac’s defensive success has been the manner in which he has achieved it. While Anunoby is a lockdown defender in the mode of Kawhi Leonard, Isaac is a more cerebral player who is at his best while playing in a strong safety-esque role on the backline. He has the capability to guard an opposing team’s best player (ask Jayson Tatum about how much fun it was going against him), but his best moments come when he is reacting to an opponent’s offense. He can rotate quickly to draw a charge or protect the rim.
His versatility under the hoop has been one of his strongest points all year. He has not only shown aptitude as a weak-side shot blocker, but has demonstrated the verticality and rotational acumen to profile as a legitimate rim protector as a 4 or small-ball 5.
Notice how his hands are straight up on that last clip. He has mastered verticality already at the tender age of 19.
Most encouraging in this regard has been his willingness to battle inside and to legitimately play as a center. He is similar to Draymond Green in this regard - while he might be undersized (or underweight) to play the 5 position, his aggression, intuition, and length enable him to punch above his weight and enact real defensive value there. Watch him battle with the 6’10, 255 pound Konstantinos Mitoglou in the post here.
He again demonstrates his ability to move off his man and recover, disrupting the Wake big man’s jumper with his reach.
Impressively, defensive rebounding might be Isaac’s single best skill. He grabbed over 9 defensive rebounds per 40 minutes, good for an insane DREB% of 25.0. For reference here is how that stacks up against the centers selected in the Top 10 since 2012.
That is absurd. The only two center prospects who rebounded at a higher rate than Isaac on defense were a generational 7-footer who was one of the best prospects of the last 20 years and a 22-year-old senior.
It’s clear in his tape that it’s not a fluke either. He has the fundamentals down, consistently boxing out his man and fighting hard for his position, even if he doesn’t immediately have the upper hand. Watch how quickly he moves into a box-out position against Marques Bolden when he thinks a shot is about to go up here.
He follows it up with a quick recovery back to the perimeter, and he’s back ready to play defense.
Between his willingness to battle, his rim protection, and his nose for rebounding, Isaac shows real potential slide up to the center position in some devastating 5-out, switch everything lineups. He won’t necessarily be able to do it against all comers (JoJo would probably squash him), but it’s a legitimate option for him in a way that it isn’t for most other wing bigs.
As with other great perimeter defensive players, Isaac’s value isn’t only in his off-ball ability, but also in how he enables a switching defense to nullify pick and roll. He has the lateral agility and effort to keep most smaller players in front of him on the switch, sometimes enveloping them at the rim.
A better point guard than Brandon Childress might have been able to punish Isaac for his anticipatory mistakes here, but his length allows him to remain the picture at all times, and he easily could have blocked a midrange attempt from behind.
Surprisingly, for a player who famously played guard until he shot up several inches late in high school, perimeter defense doesn’t come as naturally to him. He often gets stuck on picks, going neither over nor under them, and he’s not intuitive about angles to cut off a dribbler.
The premier perimeter defenders come in two types: Kawhi Leonards, who excel on-ball and shut down opposing primary scorers while being slightly less good off-ball; and Draymond Greens, who excel off-ball and quarterback a defense while being slightly less good on-ball. Isaac falls squarely into the second camp. Ben Simmons also falls into that camp, although he brings his value through anticipatory steals rather than rim protection (his 2.3 steals per 40 minutes places him in the 93rd percentile among power forwards). Between Simmons and Embiid, Isaac’s two best defensive positions are likely to be covered for large swaths of the game, and he’s not the same caliber of lockdown individual player that the best defenders are. On the Sixers, it’s not clear that Isaac’s defensive value would be realized to its fullest extent, which (sadly) diminishes his impact greatly, because he’s a major project on offense.
The first thing that sticks out on offense is how rarely he’s involved in the play. His usage rate of 20.3% slots him far below the 25th percentile for draft prospects, regardless of position. With Dwayne Bacon and Xavier Rathan-Mayes soaking up all the proverbial oxygen in FSU’s offense, it’s worth wondering whether this is a case of role or ability. In my opinion, the tape suggests it veers closer to the latter.
The good news for Isaac is that he looks likely to shoot from distance as he matures. He shot 34.8% from deep on decent volume (3’s made up 35% of his FGA’s), and supplemented that with an impressive 78% from the line, despite dry stretches from both spots to end the year. He appeared to struggle a bit with the distance, but it’s something that should be mitigated as he adds strength deeper into his career.
The bad news is that Isaac has few ball skills beyond shooting. He has an above average handle for a 6’10 forward, but outside of grab-and-go rebounds, he struggles to translate it into strong production. He’ll occasionally flash a tight-space crossover in transition or on broken plays, like this split of Miami defenders.
But more frequently, the end result of an Isaac attack is a long two or an aborted drive. His one move of substance is a jab-step to the right, followed by a drive to the left, but defenders rarely fall for the first jab, and he doesn’t have the first step to beat them to the rack. You can see him struggle against slow defenders with no shot at an NBA career like Amile Jefferson and Konstantinos Mitoglou. He should be able to punish these guys easily, and he simply can’t get by them.
Here he gets to the hoop, but is bothered by Jefferson’s (average) length. He isn’t far enough past him to finish easily, and lacks the touch to beat the contest.
He can’t beat Tatum here and simply passes out of the lane for a re-set.
Here, he gets ahead of himself and travels before he can jab.
Again, he fails to be a big man off the dribble despite having the advantage of both speed and attacking a close-out.
And finally, he settles for a midrange jumper, a frequent outcome of his attacking forays.
You can occasionally see the limits of his handling ability in open space, too. Here he makes a great defensive pressure play, but blows it with a turnover on the other end of the court.
As a passer too, Isaac comes up lacking. His assist to usage ratio of 0.37 places him well below the 25th percentile of 0.45 for wings, and is even poor if he bumps up a position to the 4, where he lands in the 39th percentile. To my eye, he’s not an unwilling passer or a black hole, and he’s capable of making a few nice reads, like this pass over the top against Wake.
Or this dump-off against Temple.
But he’s also not an enterprising passer who will be adding tons of offensive value with his ball movement. He can learn to make reads out of the short roll in space, but it’s unlikely he’ll ever unlock another level on offense due to his spatial awareness.
Isaac’s best skill on offense is likely his finishing at the rim as an off-ball cutter. He’s smart about beating his defender back door and has the length and explosion to finish above the rim with ease.
Playing alongside one of the greatest big men passers of his generation, Isaac would be a constant threat off the ball for lobs and cuts. Still, shooting and cutting can only bring so much value on offense, and it’s unlikely he can ever grow in a huge role beyond that.
Between not maximizing his defense and the lack of offensive thrust, I’m not crazy about Isaac’s fit next to Simmons and Embiid. Playing a wing rotation of Isaac, Covington, and Simmons will place a huge creation burden on Simmons, and Colangelo would need to find a point guard with real creation skills, rather than settling for a 3-&-D quasi-point guard. Because of these issues, Isaac wouldn’t be my first choice for this team. But his defensive prowess would give the Sixers 4 potential All-League defenders across the front line, and could make this team the most intimidating defensive squad in the league. For that sort of capability on one side of the ball and a decent fit on offense as a shooter, he is certainly a reasonable pick and one with which I would not be upset.