Haberstroh: Tim Duncan. Could also go with Joakim Noah here, but Duncan is somehow averaging 2.6 blocks per game at age 36 while anchoring the Spurs' seventh-ranked defense. Dwight Howard and Tyson Chandler don't play for above-average defensive teams, so it's hard to justify their vote so far. Tony Allen, LeBron James and Serge Ibaka also have a case, but Duncan's my pick.
Levy: Roy Hibbert. His offense has been bad, like Derrick Martin-bad, but the Pacers are above .500 in large part because of Hibbert's interior defense. The Pacers have the second-most efficient defense in the league and are holding opponents to 59.8 percent shooting at the rim. Now if Hibbert could just get a hook shot to drop.
Nowell: Tyson Chandler. While some of the usual stalwarts are not submitting seasons quite up to the honor, Chandler remains as steady an anchor as ever. While much of his improvement has come on the offensive end of the floor, this guy is captaining a defense whose other components are either 50 years old or Carmelo Anthony.
Strauss: Marc Gasol. Tony Allen gets much of the Internet love, but Gasol is the defensive foundation in Memphis. The nimble 7-foot Spaniard does much to allow the Grizzlies' aggressive pressure defense. With Marc backing up feisty guards, the blue bear has the No. 1-ranked defense so far.
Young: Noah. He's a one-man wrecking crew. With his energy, intensity and effort, Noah is involved on every possession, contesting shots, blocking others and grabbing rebounds. The Bulls are firmly planted near the top of the league again in defensive efficiency, and while Tom Thibodeau's system gets a lot of the credit, Noah's actually on the floor making it happen.