Over the last two seasons, Kansas was the best defensive team in the country. They didn't end the year ranked 1st in KenPom's adjusted defensive efficiency either year, but in the #1 thing a defense can control, 2 pt% allowed, Kansas was far and away better than any team over that two year stretch.
I could break down why the team was that good over the course of a post, but in reality it boils down to two words: Jeff Withey. Withey of course led the nation in block percentage in his Junior year, and in his Senior year, though he finished 5th, he played far more minutes, and against far better competition, than any player ranked above him. He was a dominant force inside, and still is the interior defender who made Anthony Davis look worse than he's probably ever looked in his basketball career (this is also my hypothesis as to why New Orleans traded for him and then buried him on the bench; so that the Davis Destroyer wouldn't get unleashed into the world).
Anyways, Kansas has a very good interior defender in his own right this year in Freshman Joel Embiid. Though Embiid ranks 10th in block percentage, his percentage (12.8%), is fairly close to Withey's last year (13.7%) and given his improvement, there is an outside shot at him catching Withey's gaudy 2012 percentage (15.3%).
But beyond simple shotblocking, the Withey effect manifested itself in opponents' FG% at the rim. Even when Withey didn't block a shot, he had a knack for bothering a shot or even just posing a threat by being on the floor that forced opponents to miss shots.
Statistically, Embiid has been right there with him (all stats via hoop-math.com):
|Year||%shots at rim||FG% at rim||Unblocked FG%|
Here's the same data in graph form:
(unblocked FG% might be confusing, but it simply means what % did opponents shoot at the rim when their shot wasn't blocked).
Because of the new foul rules (and due to the perimeter defenders) Kansas is allowing opponents to get to the rim a lot more in 2014 than they did in 2012 and 2013. However, once they get there they are finding it a lot tougher to score. Coming into the year, I (and I think a lot of Kansas fans) wondered how Kansas's defense would look not having Withey back there to erase all of their mistakes. Well, not only has Kansas not fallen off a cliff, Kansas has actually improved its rim protection with Joel Embiid anchoring the defense.
To be fair to his teammates, it would be a mistake to give all the credit to Embiid. Kansas has blocked more shots as a team this year than during Withey's ridiculous 2012 season, with Jamari Traylor and Tarik Black getting into the spirit, as well as getting contributions from Andrew Wiggins, Perry Ellis, and Andrew White.
The other factor to consider is fouls. Blocking more shots while fouling less is more valuable, for the obvious reasons of giving up fewer points due to trips to the line and the ability to keep your shot blocker on the floor:
|Year||Block%||Fouls/40||Blocks per foul|
Withey's 2013 mark led the nation by a healthy margin, and his 2012 number was in the top 10 as well. Embiid has struggled with fouls this year, but it is unfair to put too much into it given the new rules. Still, he has a ways to go to catch up to Withey in this regard.
Part of that is due to Withey being a much better 1 on 1 defender than Embiid in the post. I have a larger post planned later in the year complete with pictures and video, but while Embiid is certainly better at getting out on the perimeter and guarding guys, when backed down his somewhat weak lower body doesn't let him stand his ground as well. Part of Withey's low foul rate in 2013 came from some reputation calls (or lack thereof) but a lot of it was he was able to keep opposing bigs at bay while on the floor, and thus was more easily able to time his jump to block shots.
Of course, that is good news for Embiid as well. While he's improved a lot in 1 on 1 defense, and he's already probably equal to Withey in terms of help defending, he's been getting by mostly on instinct and athleticism thus far. We've seen evidence of his basketball IQ in his post moves and ability to pass, but now it's showing up defensively. It's unfair to say this given how good Withey was, but by the end of the year we might be talking about an even better interior defender in Joel Embiid.