11-on-11: Comparing Derrick Williams under Adelman and Porter
The theories about exactly why Derrick Williams has underperformed in the NBA are legion, encompassing everything from unreasonable expectations for a player who shouldn’t have been picked so high to fundamental concerns about his tweener status to even more fundamental concerns about his work ethic and motor. (If you want a good read about his efforts to get better, check out Jon Krawczynski‘s post on Yahoo! Sports.) One particular thread of this discussion, though, is the idea that coach Rick Adelman simply doesn’t like playing young guys—that Williams is being punished unreasonably by being installed in Adelman’s doghouse and could blossom if simply given some more time on the court.
You can hardly blame Adelman for Williams’ inability to stay in the game against the Los Angeles Clippers on Wednesday night. After picking up 5 fouls in just over 12 minutes of action, Adelman had little choice, but given Williams’ history with Adelman, it seems reasonable to wonder if Adelman’s return will not be a positive for him. As it happens, Adelman’s recent absence from the sidelines has given us a perfect opportunity to look at how Williams fared under Terry Porter during the 11 games he coached versus the 11 previous games under Adelman.
According to Porter, Adelman was still setting the lineups and making rotation decisions, but it’s hard to ignore the fact that Williams went from averaging 14.5 minutes per game in the 11 games Williams played in (that is, not counting DNPs) prior to Adelman’s leave of absence to 26.7 minutes per game under Porter. Obviously, Kevin Love’s injury plays a part in this as well (he re-injured his right hand on January 3 against the Denver Nuggets), but nevertheless, this stands as a good test of what a player who seemed to be doing well with limited minutes could do with more playing time.
Looking at the stats on NBA.com, the thing that jumps out right away is the difference in offensive and defensive rating (or, basically, points scored and allowed, respectively, per 100 possessions). Between December 14 and January 5, Williams had managed an OffRtg of 97.7 and a DefRtg of 99.0, good for a NetRtg of -1.3. This is not terrible. By comparison, another undersized, athletic power forward who is much more efficient on offense and generally thought to be a plus-defender, Thaddeus Young, has an OffRtg of 102.0 and DefRtg of 101.9, making for a NetRtg of .1 for the year. Neither Young nor Williams are expected to be defensive stoppers, but rather simply to play competent man defense.
But it got much worse under Porter for Williams. His OffRtg dipped to 97.6 while his DefRtg ballooned to 109.7 for a NetRtg of -12.1. That’s a bad rating. Things don’t get better as you look deeper into stats like true shooting percentage that measure not just how well a player is shooting, but that also give you some sense of how smart they are with their shot selection (TS% takes into account the weighted value of 3-point shots). In the 11 games between December 14 and January 5, Williams notched a TS% of 60.8%. In the 11 games following, this number dipped to 47.3%.
Where it gets really troubling, though, is that his usage rate (that is, the number of plays used by a player per 40 pace adjusted minutes) stayed more or less the same: 20.7 in the earlier timeframe and 20.1 under Porter. That means that while he was out on the floor for almost twice the amount of time, he wasn’t being used proportionally more. The plays he was using were just much more inefficient.
The shooting picture gets clearer when you look at where he takes his shots from. Below are charts showing his shot distribution (L) and shot performance in the 11 games prior to Porter’s stint as head coach.
Overall, we’re looking at about half as many shots during this stretch of games as during the following 11 (60 shots versus 122), but it’s immediately apparent that he’s getting better looks. Almost half his shots are at the rim, a third are from the arc and the remaining 12 are from midrange. Yes, he’s shooting below the league average at the rim at 50%, but he also shot 50% on above-the-break 3-pointers (although 0-for-4 on corner 3s—more on this shortly) and an impressive 58.3% on the small number of midrange attempts he took.
His shot selection under Porter fell off precipitously. Below are the same charts for those 11 games.
He’s still taking 50% of his shots around the rim, but less than a quarter of his shots are coming from the arc where before he was taking around a third from there. That wouldn’t be a problem if those extra shots were going into the paint, but instead they’re largely coming from midrange now, where he shot a paltry 34.4%.
For almost any player, but especially a player like Williams, the best shots are at the rim and from 3-point territory. Part of this is basic math: working from Ian Levy’s data over at Hickory High on expected points per shot (XPPS), the most efficient shots in the NBA are in the restricted area (1.183 XPPS), the corner 3 (1.157 XPPS) and the above-the-break 3 (1.048 XPPS).
Of course, this information based on league averages doesn’t mean that every player should prioritize these shots in this order, and Williams is a particularly interesting case. So far this season, he’s taken 80 3-pointers and only 12 of them have been from the corner. Of those 12, he’s only made one. I can’t tell you precisely why he’s taken or made so few, but I can tell you I don’t think he should be taking more of them, whatever the XPPS numbers say.
This is because if Williams’ game is going to be predicated on the push-pull of being a long distance threat and also a finisher at the rim, the bulk of his 3-point attempts need to come from above the break because it’s just much harder for him to penetrate from the corner. If his above-the-break 3-point shot is a threat, it forces defenders to close, which can allow him the space to blow by to the paint. If he can improve his passing (and the Wolves can improve their corner 3-point shooting), it also opens up the possibility of kicking the ball to the corners if the defense collapses. By contrast, if Williams is setting up in the corner, he has to either penetrate going towards the middle of the floor—where the defense is—or along the baseline, where there’s a lot less room for a 6’8” power forward than for a 6’2” guard like Luke Ridnour. It’s also much harder to make passes back out when driving along the baseline. Williams will likely never become a spot-up 3-point threat, but it’s reasonable to expect he could develop into a dual long-range/close-in threat.
The biggest impediment to that development right now, though, doesn’t seem to be only related to giving him more time on the floor. More playing time in the 11 games during Adelman’s absence showed a drop off in his game compared to the 11 that preceded it. Whatever the deeper reasons behind Williams’ struggles, it seems like the blame can’t simply be levelled at Adelman not giving him a chance.