Looking to solidify their front court defensively, the Oklahoma City Thunder acquired Kendrick Perkins at this season’s trade deadline.  Perkins’ arrival turned the Thunder’s frontcourt into one of the most formidable defensive units in the NBA (probably behind the Lakers).  Perkins is definitely one of the best one-on-one post defenders in the NBA (if you are unsure about this statement, go watch him against Dwight Howard), but what makes his arrival so important for the Thunder’s defense isn’t his one-on-one defense, it is the fact that his presence on the court allows Serge Ibaka to really flourish on the defensive end.  With Perkins defending opposing centers, Ibaka is now allowed to use his athletic ability and become a menacing threat on the weakside, blocking shots.  We saw a perfect example of this last night during the Thunder’s win against the Nuggets:

Here, Nene gets the basketball in the post and tries to make his move against Kendrick Perkins.  Perkins is so physical and so tough to get by that it takes him a little bit longer to make his move.  This allows Ibaka the time to come over and time Nene’s shot attempt well enough to get the big block.  In addition to forcing post players into taking a longer time (this is because Perkins is beating up his man), it seems that most post players’ focus is to make a move to beat Perkins and they are so focused on that, they aren’t really thinking about Ibaka coming over for the block.

Ibaka is so dangerous as a weakside shot blocker, but until Perkins arrived, he was unable to be that threat to the best of his ability.  The reason why is because Ibaka was forced into defending more centers while being the on ball defender more (vs. being the one coming from the weakside).  A few reasons why this is less than desirable for Oklahoma City.  First, with Ibaka covering centers, there is a size difference that forced him into situations where he would front the basketball.

When Ibaka fronts the post, you are basically taking away his ability to use his athleticism when defending.  That is exactly what happens here as Roy Hibbert gets the lob pass and finishes as Ibaka is on the wrong side of him.

In addition to Ibaka covering bigger guys, when he is the on-ball defender, post players are able to do things to take away Ibaka’s athletic ability.  Most notably, getting into his chest right before they go up for the shot, preventing him from jumping:

In both of these clips, you see that Ibaka doesn’t really get off the floor to try and bother the shot.  The reason why is because these post players are getting into his chest, hitting him, knocking him off balance, and preventing him from getting off of the floor in a timely fashion.

This is why a guy like Ibaka is much more of a threat off of the basketball.  There is nobody getting into his chest, taking away his athletic ability.  He is free to come over from the weakside and get the big block.  Here are a few more examples:

On this play, Nikola Pekovic gets the ball in the post and makes his move against Perkins.  Pekovic has kinds of trouble even getting a shot up against Perkins, and by the time he does, Ibaka has already been in position to get the weakside block for a few seconds.

Again, Perkins is the man defending on the ball in the post, this time against JaVale McGee.  Again, Perkins is able to beat up the man he is defending as he tries to work in the post.  McGee tries to make his move towards the middle of the court, but Perkins is able to cut that off and force him to spin baseline, right into Ibaka who is coming from the weakside for the block.

There were a few people who were left scratching their head when the Thunder extended Perkins without even watching him play, but the Thunder knew what having a guy like Perkins playing next to Ibaka for years to come meant.  This was a great move by the Thunder because you are not only getting a terrific defender, but you are allowing the player next to him to flourish.

With the Thunder’s potential path involving three strong post players (Nene, then Duncan, then Bynum/Gasol), post defense is going to be very important.  With Perkins and Ibaka sharing the frontcourt, the Thunder will be able to hold their own down low.