The Declining Market for Centers
On July 1, 2016, the Los Angeles Lakers kicked off free agency and essentially set the center market by signing Timofey Mozgov to a 4 year, $64 million contract. After the market was set, more center signings followed. Ian Mahinmi signed for 4 years and $64 million with the Washington Wizards. Bismack Biyombo signed for 4 years and $72 million with the Orlando Magic. Joakim Noah signed with the New York Knicks for $72 million. Even Miles Plumlee managed to get a huge 4-year deal for $52 million.
Fast forward to August of 2017. Free agency has essentially ended and the most lucrative contract signed by a center was Kelly Olynyk at $50 million over 4 years with the Miami Heat followed by Pau Gasol's partially guaranteed 3 year, $48 million dollar contract with the San Antonio Spurs. All other signed free agent centers took significantly less money when it sunk in that the summer of spending ended in 2016.
The question is why is there such a stark difference in the amount of money centers got in 2016 to what they received in 2017. The simple answer is teams have less money to spend than they did last summer. The NBA salary cap jumped from 70 million to 94.1 million in 2016 freeing up a significant amount of cap space for many teams. In 2017 the cap only raised from 94.1 million to 99 million, which hurt the flexibility of many teams. Players received fewer years and less money than they originally expected after the 2016 boom but no one took a bigger hit than the centers.
A prime example of this is the negotiations between the Dallas Mavericks and Nerlens Noel. Noel, a restricted free agent still remains unsigned with training camp ready to begin in a month's time. Happy Walters, Noel's agent, said that the Mavericks have yet to come up with a realistic contract offer and was quoted saying "We're very disappointed with where things stand. Nerlens loves Dallas and spent June there working out, but we're still waiting on a serious offer." The Mavericks, on the other hand, have not felt a considerable amount of pressure to give in to Noel's demands yet and for good reason. It can be assumed Noel never got a "serious" offer from any other team during free agency and now most teams have spent used their cap space and their rosters are set for the upcoming season. Unless Noel plans to sit out the season, it is more likely the Mavericks will win whatever compromise the two parties come to. Noel's situation is also similar to the ones other restricted free agent centers like Alex Len of the Phoenix Suns and Mason Plumlee of the Denver Nuggets face as well.
Part of the reason for this is the performance of the centers signed in 2016. Biyombo, Mozgov, and Plumlee underperformed their respective contracts and the latter two were traded. Noah and Mahinmi were frequently injured and eventually dropped out of the rotation. Additionally, traditional back to the basket centers that can't shoot three pointers or defend smaller guards on the perimeter are becoming hard to trade. The "small-ball" era has made the idea of a slow footed 7 footer guarding a point guard like Stephen Curry at the 3 point line seem impossible. Even Tristan Thompson who is one of the Cavaliers best defenders was benched for long stretches of time during the 2017 NBA Finals because the Cavaliers tried to match the Warriors smaller lineups and space the floor. The shift in playing style has made it increasingly difficult to trade centers with big contracts (with the exception of stars like DeMarcus Cousins). The Lakers had to trade the former #2 overall pick in D'Angelo Russell to dump Mozgov's contract onto the Nets. Using this trade as a baseline, teams it would appear teams have to attach valuable assets in order to trade centers like Mozgov with similar contracts.
This is not to say traditional centers don't have a place in the league. Players who excel at rebounding, defending the rim, scoring in the post, and/or setting hard screens can make valuable contributions to their teams. However, the center position is evolving to the point where centers that can't shoot 3 pointers or are elite defensively are seeing their value diminish. This is part of the reason we saw players like Brook Lopez and Marc Gasol who had spent most of their careers scoring from the low post expand their range and become reliable 3-point shooters last season. The NBA is changing and is slowly urging centers to change with it.