2018-19 Duke: The injury bug bites Zion (and others)
When Zion Williamson went down with a knee injury, Duke fans held their breath. He returned, but injuries elsewhere had a big impact at the end of Duke's season.
This is the 3rd in a series of 4 articles about the 2018-19 Duke Blue Devils. Part 4 will be released on Friday, Nov 27. Check out my archive for my previous articles and others in the Hoops Hindsight series.
Cameron Indoor Stadium was raucous and ready for a showdown between the #1 ranked Blue Devils and their hated rival, the #8 North Carolina Tar Heels. And then a minute into the game it happened…
Zion’s freshman year had been phenomenal, and now Duke would be without him for some period of time. The shell-shocked Blue Devils struggled in that first game without their star, losing 88-72; That would be their only double-digit loss of the year. All of college basketball wondered how Duke would fare without Zion.
Zion missed all or part of 6 games, and the Blue Devils went 3-3. He returned for the ACC Tournament, Duke won it, and all seemed right with the world. But here at Hoops Hindsight, we don’t just look at the results, we look at the data. What happened with Duke when Zion was out? Were there lingering effects when he returned? How much did his injury hurt Duke in the postseason? Let’s see!
Duke had struggled without Zion before
Duke struggling without Zion for a few games was not a surprise to anyone. Prior to the UNC game, Duke was -15 in 133 possessions in ACC play without Zion (excluding garbage time). They had an adjusted margin of +4 points per 100 possessions.
In the 2 games prior to his injury, Duke was -10 in 13 possessions against Louisville and -9 in 19 against NC State without Zion and +40 in 111 possessions in the two games with Zion.
In ACC play without Zion, Duke shifted from an interior team to trigger-happy outside shooters. 43% of their shots were from deep, up from 37% for the season. Duke hit 36% of them (up from a season average of 31%) to offset the fact that their 2 point shooting dropped from 59% to 46%. Looking at the shot charts with and without Zion for their first 13 ACC games, you see a complete shift in offense:
On defense, Duke was a disaster in ACC play without Zion. Opponents had an effecive FG% of 54% without him in compared to 46% with, and Duke got only 62% of defensive rebounds when Zion sat vs. 72% when he played. Here are the opponent shot charts, which show what a deterrent Zion was around the basket:
When Zion was sitting in ACC play, Duke almost always went to Jack White (not the musician); White played 114 of the 133 possessions Zion sat. This created some of the offensive shift to the perimeter, as White took 80% of his shots from deep while Zion took just 15%. This also explains Duke’s inability to defend the interior, as Zion was graded by Synergy as easily Duke’s best post defender (graded in the 100th percentile) while White graded in the 18th percentile. In fact, none of Duke’s defenders except Zion were graded as better than the 31st percentile agianst post-ups, according to Synergy. Missing Zion was going to destroy Duke’s defense against teams who post up.
Shifting their lineups and focusing on the remaining 3 freshmen
Duke decided to shift their strategy a bit after Zion’s injury. Against North Carolina, who liked to use two big men, Duke played Jack White in Zion’s absence. White played 50 minutes in the 2 UNC games without Zion, and just 34 in the other 4 (including missing the Syracuse game). Against the other 4 opponents, Duke favored swingman Alex O’Connell. Honestly, neither one made much of a difference.
In the 6 games Zion missed, Duke had an adjusted margin of +20 points/100 possessions. That’s not awful, but it’s a far cry from their season-long performance. Their adjusted margin was +17 with O’Connell in and +14 with White in, so neither was any great shakes. Similar to their previous ACC games without Zion, Duke fired away from deep; they took 44% of their shots from the outside, and 49% when White played. But unlike their earlier stretch, they were off-target, hitting only 27%. That is most definitely a problem.
Duke’s defense was better than it had been previously without Zion, as opponent had a 46% eFG% in the games he missed with injury, but Duke missed Zion’s disruptive play. The Blue Devils only forced a turnover on 15% of opponent possessions while Zion was injured, compared to 18% previously.
The biggest issue was that Duke was not able to rest the other 3 of their star freshmen much when Zion was injured. During ACC play, Barrett, Jones, and Reddish each rarely sat unless Zion was in the game. Here’s a breakdown of the non-garbage time possessions each sat in ACC play prior to Zion’s injury:
Barrett: Sat for 43 possessions; Zion was in for 42 of them
Jones: Sat for 225 possessions; Zion was in for 209 of them
Reddish: Sat for 214 possessions; Zion was in for 185 of them
Overall, Duke was hesitant to rest more than 1 of their 4 star freshmen at once, and for good reason:
With all 4 in, Duke was awesome. With 3 in, Duke was solid but a notch below. With 2 or fewer in, Duke was decidedly average and struggled to compete with their ACC brethren.
With Zion injured, Duke tried to play their 3 remaining stars as much as they could to keep them in the games:
The other three freshmen struggled to step up their game in Zion’s absence. Barrett, Jones, and Reddish picked up more shots, taking 74% of Duke’s shots vs 63% for the season, but they only had a 46% eFG% vs 48% for the season. They were especially poor from deep, hitting only 26% of their threes.
Zion’s return brings a sense of normalcy, but rotation injuries doom the Devils
With Zion back in the fold for the postseason, Duke got back to the rotations they wanted. They played a stunning 97% of their postseason minutes with 3 or more of their star freshmen (450 of 463). The Blue Devils toned down the outside shooting, taking a more normal 34% of their shots from deep, and defended the rim with opponents hitting only 57% of their shots at the rim.
Zion was back, largely as good as before. After returning Zion put up 26 points per 100 possessions, compared to 27 previously. He hit 79% of his shots at the rim, equal to his season long accuracy, and even added some three-point range hitting 43% (10 for 23).
Just as Zion came back, however, Duke was beset by injuries in his supporting cast. Marques Bolden suffered an injury against North Carolina in the regular season finale and missed the ACC Tournament. Jack White suffered a hamstring injury during the ACC Tournament and only played 6 minutes during the NCAA Tournament. Cam Reddish missed the Sweet 16 game against Virginia Tech. This meant that Duke was not able to play its favorite lineups as much during the biggest games. Of the 10 lineups Duke played during their final 3 games, 5 had not played a single possession together before Zion got hurt. These 5 lineups went -5 in 75 NCAA Tournament possessions.
Duke had a tremendous team during the 2018-19 season, and was rightly viewed asone of the top contenders for the title for much of the season. At the end of the day, some key injuries threw off their rotation too much to overcome. While the injury to Zion Williamson was the biggest headline, he was able to return to form in time for the most important games. Injuries to his supporting cast forced several makeshift lineups which ultimately doomed the Blue Devils, and sent them home earlier than expected.
In my next article on 2018-19 Duke, I’ll look at how shooting woes coincided with their poor performances and what led to these problems.