As much as the 3-pointer has changed the game, every team in the NBA is still obsessed with creating and defending shots at the rim. The latter is tough to do without a long, shot-blocking big man who can make opponents think twice about trying to score on the inside. You don't need a Dikembe Mutombo type to fill that role -- the reigning champions asked Draymond Green and Kevin Durant to do much of their dirty work -- but it helps to have players who made their names patrolling the paint.
While this year's crop of free agents isn't exactly full of rim protectors, teams looking to shore up the interior do have some options:
While his block rate has been steadily declining for the last five years, some of this is because he has spent more time guarding stretch 4s and switching onto smaller players. Some of it, though, is because Serge Ibaka's athleticism isn't quite what it was, meaning that signing him to a four-year deal at more than $20 million per season comes with some risk. Nonetheless, the Raptors ought to do it, unless they are OK with taking a serious step back. Ideally, he will become a full-time center next season, but that cannot happen as long as Jonas Valanciunas is on the roster.
He hasn't earned the right to be called "the next Tyson Chandler," but the Mavericks are hoping he will get there. Acquired at the trade deadline for a fake first-round pick, the restricted free agent is widely expected to stay in Dallas. Good thing, too, as he helped the Mavs on both ends of the court and is one of their few young building blocks. At 23, there is plenty of development for Nerlens Noel to do, but he is a quick, active defender with excellent anticipation. That's worth paying for, particularly given how long Dallas tried to get by with stopgap solutions at center.
You won't find anyone with a bad word to say about Taj Gibson. For years he played behind lesser players in Chicago, and he never let it affect his effort. This is the first time he has ever been a free agent, and while he might feel a certain pull to stay with the Thunder, who acquired him in a lopsided trade at the deadline, it's time for him to get paid -- in Oklahoma City or elsewhere. Gibson brings toughness, defensive smarts, some shot-blocking and a better post game than you might expect. While he's not the kind of force that deters opponents from driving to the basket, he has the ability to play both power forward and center and switch onto wings, too.
Perhaps the single best under-the-radar free agency signing last offseason (though the next two guys on this list were pretty good, too), Nene had the most efficient year of his career in Mike D'Antoni's system. The Rockets were wise to limit the 34-year-old's minutes throughout the regular season, and he rewarded them by going bananas in the first round of the playoffs. A crucial part of the team because of his pick-and-roll defense and finishing ability, he was fourth in defensive real plus-minus among centers and had the best defensive rating on the team. He could take the bi-annual exception ($3.3 million) to stay in Houston or look for a raise elsewhere.
There isn't much to his offensive game, but the man can rebound, block shots and catch lobs. He's not that much different than Bismack Biyombo, who signed a $72 million contract last summer. DeWayne Dedmon replaced Pau Gasol in the starting lineup for good reason last year, and his tiny role in the playoffs remains a bit confusing. Only Rudy Gobert, Draymond Green, Andrew Bogut and Robert Covington had a better defensive real-plus minus.
If there was a comeback player of the year award, JaVale McGee would win it in a landslide. He embraced his role -- beating his man down the court in transition, contesting shots like crazy, finishing alley-oops -- and was extremely effective in it. Golden State gives him an absolutely perfect situation, but he might have played his way out of there. Still not the most disciplined defender, but he improved his pick-and-roll defense and became a bit more selective in terms of block-chasing.
One of the game's premier defenders, screen setters and passing big men, Andrew Bogut's 2016-17 season was derailed by injuries. We'll never know if his presence would have made much of a difference for the Cavaliers in the Finals, but it makes sense that a contender went after him after the Mavs bought him out. Has been written off because of injury before and bounced back just fine. Might be more difficult at 32 years old, but ESPN's Marc Stein reported that he has been cleared for running and jumping after fracturing his left tibia 58 seconds into his Cavs debut in March.
Everybody seems to think Amir Johnson has fallen off, but he was fifth among power forwards in defensive real plus-minus and had the best net rating of any Celtic. He's an old 30 because he was the last player to ever be drafted out of high school and his history of playing through nagging injuries, but even though he has lost a step, he is still generally in the right place at the right time on defense. Still a fantastic screen setter, too.
I almost didn't put him on this list because he's only an occasional shot blocker, but Zaza Pachulia deserves inclusion because of the way he played his role last season. While it obviously helps to be surrounded by elite players, it should be noted that he gave the Warriors exactly what they wanted from him.
If he were being judged as an ordinary reserve center, Alex Len would have a good reputation. There's nothing especially modern about his game, but he has pretty good touch at the basket and he's able to change shots with his sheer size, if not any sort of magnificent defensive instincts. He has improved, but not to the point where he is close to justifying being picked No. 5 overall. The 2013 draft was weird.
One of the Heat's many smart buy-low signings last year, Willie Reed proved to be a rotation-caliber player based mostly on his scoring ability on the inside. He's not a bad rim protector, though, using his 7-foot-3 wingspan to make up for his relative lack of height for a center. Likely more than a minimum-salary guy now.
Not a traditional rim protector because of his lack of bounce, Aron Baynes does his work by simply being big and forceful. The Pistons will almost certainly lose him in free agency, having signed Boban Marjanovic last summer to take his place, but he will provide some other team with solid positional defense as a backup center.
There was once a time where Roy Hibbert was the most dominant defensive force in the entire league. Alas, that time has passed. The Hornets tried him out as a reclamation project last year, then dumped him on the Bucks, who dumped him on the Nuggets. It's all rather sad. It would be quite a story if he could land somewhere that could get him healthy and give him an opportunity to prove that there is still a place for him in the league.
He makes up for his lack of quickness with his energy, and he is both physical and aggressive -- two good attributes for a backup center. Not ready for a bigger role than that, though, and his relative lack of mobility puts him in tough spots.
If you're looking for shot-blocking and rebounding -- and very little else -- on a minimum contract, then Jeff Withey is your man. Makes sense in Utah's defensive system behind Rudy Gobert.
Note: There are other bigs available in free agency, but if they don't bring any rim protection, they're not on this list. Apologies to Pau Gasol, Mason Plumlee, David West, David Lee and Kelly Olynyk, among others.