Even as a rookie, John Henson's box score production was impressive. On a per-minute basis, Henson grabbed rebounds at an equal or better rate to players like Dwight Howard, DeAndre Jordan, and DeMarcus Cousins. He blocked almost two shots per 36 minutes and scored over 16 points. It was enough to put Henson on the radar as a potential "breakout" player this season. The hype looks well-deserved: Henson's per-game production has doubled nearly across the board; he's been one of the Bucks most consistent offensive players and he's...well, he's trying to salvage their rebounding numbers.
We've often glossed over the other end of the floor when it comes to Henson, however. While his shot-blocking talent was obvious as a rookie, other aspects of his game were far less refined. Henson experienced some predictable struggles when facing the NBA's more physical forwards, understandable given his slight build. But the bigger issue was his sloppy help defense and poor positioning. Considering Henson's understated quickness, it was a bit surprising to see him caught flat-footed so often, especially considering he spent three years playing at a high-level college program. Still, defensive struggles as a rookie big man are nothing out of the ordinary.
Has he improved this season? There's little doubt in my mind. Henson's interior defense seems much better, from one-on-one battles to help defense to shot blocking. He's getting into position much quicker and generally showing smarter anticipation of opposing offenses. When defending the post, he's learned to use his length to effectively challenge shots without fouling; Larry Sanders' breakout season was built on the very same development.
In fairness, things have been a bit easier for him this year. He's playing a slightly higher percentage of his minutes at center, meaning he doesn't have to stray away from the basket as much. He's also got much better perimeter defenders in front of him, limiting his exposure to some extent. But that shouldn't take away from his excellent rim protection. According to NBA.com's Player Tracking Data, Henson is allowing just 43.9% shooting at the rim on shots he defends, on par with Andrew Bogut and Tim Duncan, and better than Serge Ibaka and Dwight Howard.
Despite those improvements, Henson's on/off-court team defensive rating split exhibits the same strange behavior as O.J. Mayo's early season offensive rating splits. According to NBA.com, the Bucks have been 6.5 points/100 possessions better on defense with Henson on the bench this season. So once again, a closer look is warranted.
Despite a drip in Henson's own rebounding numbers, it doesn't appear he's hurting the Bucks on the boards. According to 82games.com. the Bucks' defensive rebounding rate is 4.5 points better with Henson on the court, while NBA.com pegs it about equal either way. The same goes for opponent eFG%, where Henson doesn't appear to move the needle much.
One area with a significant discrepancy is opponent free-throw rate. When Henson has played this season, the Bucks' opponents have been getting to the line a ton, putting up a .342 FTR. That number would rank in the NBA's top 3 this season (note that NBA.com calculates free throw rate differently than Basketball-Reference.com). With Henson off the court, that number drops to .281, right around league-average. Henson's own fouling doesn't appear to be much of an issue; he's only committing 3.2 fouls per 36 minutes. There's some context missing here, since we don't know what kind of fouls the Bucks are committing with Henson out there, but it stands to reason their strategy isn't changing significantly according to lineup changes. Like the Bucks' own FTR disparity with and without O.J. Mayo, this seems pretty fluky.
The other spot with a major disparity is opponent turnover rate. With Henson on the court, the Bucks' opponents have turned the ball over on 14.2% of their possessions, a top-5 rate in the NBA this season. When Henson sits down, the Bucks opponents suddenly turn into reckless maniacs, committing turnovers on over 19% of their possessions. Prorating each to the Bucks' 94-possession average, that's almost five more turnovers per game. That's five fewer chances for a tap-out to an open 3-pt shooter, five fewer putback dunks over stone-legged Bucks defenders. And given the Bucks' struggles with defensive rebounding, forcing turnovers has the added bonus of bypassing one of the weakest elements of Milwaukee's defense.
Henson isn't much of a steal artist, even for a big man, with a 1.4 steal percentage this season and just one swipe per 36 minutes. Of course, few big men are, and it's certainly strange to see Henson swing the turnover game so significantly. It's particularly strange because the Bucks have actually forced turnovers at a top-10 rate this season despite the absence of Brandon Jennings and Monta Ellis, both of whom lived in passing lanes almost to a fault.
Is Henson's style of play having an effect on how opponents are able to take care of the ball? Unfortunately there's no available data to determine how much zone defense the Bucks play with Henson on the court, but we've seen glimpses of an effective zone scheme pairing Henson and Giannis Antetokounmpo in a hurricane of arms and legs. Conventional wisdom says that zones produce fewer turnovers absent tight ball pressure, and the Bucks seem to play more straight-up one-on-one defense than the "angular" practices under Scott Skiles and Jim Boylan. If that's the case, it could explain a small split (though nothing quite so extreme), especially if perimeter defenders are playing more conservatively with Henson and Ekpe Udoh behind them instead of Larry Sanders.
Honestly, these numbers will be of little importance once Sanders returns. Considering how well Henson has been playing lately, there seems to be no excuse to avoid pairing the two in the starting lineup for an extended period, and the results of that experiment remain one of the most critical factors in Milwaukee's long-term decision making.
Please hurry back Larry!