I noticed this via the eye test the instant he came into the league, long before any of those horrendous statistics showed up. The latter only confirmed what I knew from day one.
Jahlil Okafor is one of the slowest big men I have seen in the NBA. Even if you just throw on some simple highlight videos of Okafor's better offensive performances in the league, it's painfully obvious that he moves with all the agility of a Mack truck:
https://www.youtube.com/watch?v=w1AvNpo411Q He has impressive footwork on offense, a very nice touch around the basket, and clearly knows how to finish in the paint - there is no denying that. He has a very high skill level in the post without question, but he's horribly slow for a 20 year old - even one with his size.
For comparison purposes, watch some highlihg videos of Greg Monroe from last season - a guy who is a very similar style of player to Okafor (6'11" and 250 pounds, not very athletic, plays below the rim, primarily an inside scorer, defensively limited):
https://www.youtube.com/watch?v=PEelVX1DV7cFrom these videos you cans see both guys running the floor. Seing Okafor at 0:19 I'm not sure if he's lazy, out of breath, or if he is just genuinely that slow...but he looks like he has no interest at all in getting back to the other end of the court. Similar scenario at 0:59 in Monroe's highlights - he sprints hard to get back on offense, and I'm actually pleasantly surprised by his footspeed - he gets back very quickly for a man of his size. He does it again at right after that, at 1:16. There isn't a single highlight in the Okafor video that shows him sprinting back like that - looking at the two side by side they look like chalk and cheese, Monroe makes Jahlil Okafor's effort look downright embarrassing.
The video also showcases their quickness. At 2:31 Monroe manages to pull off a quick spin move - he's quick enough to beat his defender, forcing another defender has to come over to help. He pulls off a similar spin move at 3:05 and is able to beat his defender (this time, Drayond Green) again, getting all the way to the basket for an easy layup. Okafor tries a similar moves in his highlight video at the 1:00 mark and 2:03 mark, but in both cases he's too slow to shake his defender. He eventually scores anyway thanks to some nice footwork (in the former case) and his superior length (in the latter case), but regardless of this the footage clearly demonstrates that Okafor is much less agile then Monroe.
When you consider the fact that Monroe 4-5 years older then Okafor and is known for his lack of athleticism/mobility, seeing such a dramatic difference between those two guys is more then a little concerning.
On the plus side Okafor is able to use his length (7'5" wingspan) to bail himself out from time to time which Monroe (7'2" wingspan) can't do nearly as effectively - so there is the odd occasion where Okafor is able to cover up a horrible defensive possession with a lucky last minute block, or cover up his lack of footspeed on offense by simply shooting over a guy. However that still doesn't put to rest my significant concerns over Okafor's complete lack of mobility.
In fact, if you look at highlights of a 40 year old, 350 pound Shaquille O'neal (see: 1:50, 2:04 and 4:05 below) he honestly doesn't look much less mobile in some of those shots then Okafor does right now:
https://www.youtube.com/watch?v=1x-6gVWBQv0Personally I think Okafor's biggest problem is his conditioning. He doesn't look Sully-bad by any means, but to be completely honest he looks like he's about 75%-80% of the way there. He physique looks soft/squishy, he moves very slowly, and appears winded far more often then a 20 year old athlete should. If he could drop 10-15 pounds I think his game would improve dramatically, but it's hard to say if that will ever happen because on the court he just doesn't look all that motivated. He looks lazy - he doesn't look like he wants to run, or battle for rebounds, or dive for loose balls. He looks like he believes he doesn't NEED to do those things, because he can depend on his length/bulk to get him by.
I'm not a fan of his attitude and I'm not a fan of his body language - it leaves me cause for concern that he's going to be another Sully...a hugely skilled big man who could be so much, but was just never cared enough.