Kendrick Perkins

Oklahoma City shone this week, shoring up their weakest position and picking up a quality backup guard in the process, all for spare parts. D.J. White (a power forward who was never going to crack the rotation), Jeff Green (a talented sixth man type caught on entirely the wrong team), Nenad Krstic (who was a good candidate to leave this summer anyway) and Mo Peterson (who was definitely going to leave this summer anyway), combined with a future protected first round pick from the Clippers, saw them land two starting calibre centres in Kenny Perkins and Nazr Mohammed who should greatly improve their defense, along with Nathan Robinson, who won't.

Perkins fits the big defensive anchor role for Oklahoma City that Cole Aldrich hasn't. His perennially underwhelming numbers belie his impact; he will slide right in and sure up a frankly rather average defense. The same is true of Mohammed, who will be an incredibly good rental for the Thunder. Mohammed did not want to leave Charlotte, going so far as to mention retiring if he did not re-sign there this summer, but now he's gone to a very good situation, where he'll play big minutes on one of the league's best. Throughout his entire career, people have underappreciated how productive Nazr Mohammed has been, and still is. When you see him average 8/6 in the playoffs, you'll remember.

Even when looking at those numbers, the Mohammed trade was also good for Charlotte, who picked up a solid power forward prospect in White in exchange for a veteran who was expiring anyway. If they really want Nazr back, they can sign him back in 2 years, when the lockout ends. And the Gerald Wallace trade was not bad either - two first round picks, a potentially useful backup small forward and complete salary absolution from a struggling and expensive player who seems to have already peaked is a pretty good return in any deadline deal. Gerald Wallace isn't Pau Gasol; this trade wasn't that trade. It's a good deal for Portland, but not a fleecing.

It was the Thunder's other trade that reverberated. Seemingly perturbed by the risk of losing him this summer due to his unrestricted free agent status, and perhaps exacerbated by his troublesome knees this season, Boston annoyed Kevin Garnett greatly by trading starting centre Perkins for backup centre Krstic and backup forward Green, filling their need for some forward depth but at the expense of creating a gaping hole at centre.

Not so long ago, the Celtics had five centres; Perkins, Shaquille O'Neal, Jermaine O'Neal, Rasheed Wallace and Semih Erden. They had more centres than they had roster spots for them, and had done it this way on purpose. But Rasheed followed through on his retirement plans, Shaq has struggled to stay healthy, and Jermaine lost that same struggle four years ago. Not even Erden exists any more; like Daniels, he and the Skillz Train were pawned off to the Cavaliers in exchange for a second round draft pick, simultaneously opening roster spots and saving money. Without him on the bench, the Celtics become even shallower. The team that has to go through Dwight Howard now has to do so while relying on Nenad Krstic and Big Baby at centre.

They shook up the roster, but we're not sure why.

(Incidentally, Perkins passed his medical with the Thunder, in spite of the issues in both his knees. This is telling, for this is the team who once vetoed a trade for Tyson Chandler on the basis of his medical. If there was something in there to worry unduly about, they would surely have found it.)

Earlier in the season, Boston offered Kenny Perkins a contract extension, which he declined. Perkins said no because the extension that the Celtics offered, whilst the maximum they were allowed to offer under CBA extension rules, was probably lower than what Perkins could corral in the summertime on the open market. But by creating this small amount of cap room, OKC can now offer him a bigger extension than Boston could.

NBA contracts are only renegotiable if

a) they're going upwards, and
b) the team has cap room.

Because teams so rarely have cap room, and because it rarely behooves teams to pay their already-under-contract players more money, it almost never happens. Indeed, before this season, I could not name you a single occurrence of it happening; it probably has at some point, yet that's a testament to how rare it is. However, in this modern, sabermetric, MIT-laden internet-era NBA, executives are far more cap creative than they used to be. Therefore, this barely-used strategy has been used twice far already this season. Washington used their leftover cap room to increase Andray Blatche's salary, almost doubling his pay over the final two seasons of his contract and simultaneously tacking on a three year extension. Rather than chancing losing him on the 2012 open market, the team tied him in for five years for a total of $35,730,997, tying down a productive young player for a significant period of time. The Thunder themselves later one-upped this move with a $17.55 million extension for Collison that deliberately, humorously and yet craftily made him the fourth highest paid centre in the world ($13,670,000), behind only Amare Stoudemire ($16,486,611), Dwight Howard ($16,647,180) and Yao Ming ($17,686,100).

By simultaneously acquiring cap space with the underpaid Kenny Perk, OKC can now do a Baltche with him. OKC can use their cap space to renegotiate Perkins's current $4,640,208 salary up to as much $6,696,720. From there, they can concurrently offer a new four year extension totalling a a maximum of $33,818,436, or any number below that that they feel happier with.

Add in the extra negotiated salary, and that's over $35 million for four years that OKC can theoretically offer him, as-near-as-is $9 million per. In contrast, Boston could only offer circa $6 million per. It's a significant difference.

If Perkins thinks he can get that much on the open market, he's wrong. He's not even worth that much, especially with his current injury concerns. Yet if OKC anticipates his return to full health, and wants to tie in the defensive centrepiece that they have thus far lacked during the entire Kevin Durant era without running the risk of him hitting the open market, they can do so right now.