For a long stretch of the season, the Chicago Bulls proved just about everybody wrong, in a whole lot of ways. The DeMar DeRozan sign-and-trade acquisition — panned by league insiders as one of the worst moves of the offseason — worked out splendidly, with DeRozan emerging as an early season MVP candidate. The team’s defense, expected to be among the worst in the NBA, instead ranked fifth in the league nearly a third of the way through the regular season.  

Over the next two months, the Bulls impressively maintained their place in the standings despite losing players to both injuries and COVID-19 protocols. Chicago went 21-13 between Dec. 8 and the All-Star break to finish the first half of the season with a 38-21 record, tying them with the Miami Heat for the best mark in the Eastern Conference.

The Bulls’ defense dropped off during that stretch, though, ranking 27th in the NBA. The dramatic backslide meant the Bulls entered the break with the league’s fourth-ranked offense, 20th-ranked defense, 11th-best net rating and 10th-best point differential, but still managed its fourth-best winning percentage. Chicago’s (and DeRozan’s) performance in clutch time led to the team outperforming its Pythagorean expectation by 4.4 wins before the All-Star break alone. A team’s point differential is generally a better predictor of its future performance than current record, but the Bulls since the All-Star break have fallen even further than we might have expected: Chicago is just 6-11 since the midseason hiatus, with the league’s 28th-ranked offense, 20th-ranked defense and 26th-best net rating and point differential.⁴³

And of course, it’s not as simple as “the Bulls have regressed to the mean.” Chicago has played the majority of its games since the break without at least three of its expected top-six rotation players.

Lonzo Ball has been out since mid-January, and there is currently no timetable for his return as his knee “has not responded” to rehab, according to coach Billy Donovan. Ball was shooting 42.3 percent from beyond the arc prior to his injury, the best mark on the team. It’s not a coincidence that Chicago’s 3-point attempt rate and 3-point percentage have fallen off dramatically in his absence, as Ball’s ability to both hit from deep and create open looks for others was a key component of the Bulls’ offensive attack.

Before Ball went down, the Bulls took relatively few threes but made a lot of them, which helped their offense remain among the league’s best. Since he left the lineup, the Bulls are taking even fewer threes and have dropped to a league-average conversion rate. When the average NBA team takes nearly 40 percent of its shots from outside, you’re playing at a disadvantage if your offense operates in this fashion.

Alex Caruso returned from his 22-game absence due to a fractured right wrist on March 12, and while he has resumed playing excellent defense and shot well from the perimeter (he’s 11-of-29 from three), he’s struggled badly to finish inside, converting just 34.5 percent of his 2-point shots. Second-year forward Patrick Williams returned from his own extended injury absence (65 games) last week, and by his own admission he has not looked like himself on either end of the floor. After tearing ligaments in his left wrist, we could have expected Williams’s offensive struggles, but his muted contributions on defense are a more pressing concern — especially considering the team’s preexisting issues on that end.

Meanwhile, Ayo Dosunmu — who looked excellent as a fill-in starter, averaging 11.8 points, 4.2 rebounds, 6.8 assists and 1.3 steals on 53-40-83 shooting splits in 38.1 minutes  across an 18-game stretch right before the All-Star break — is slowing down. Since March 14, Dosunmu has seemingly lost his legs, shooting only 44 percent from the field and 23 percent from deep.

These types of things happen when your team’s top six rotation players have missed 170 player-games combined. Williams has missed 65 games, Ball has missed 41 and counting, Caruso has sat 38, Zach LaVine has been sidelined for 13, Nikola Vučević has missed eight, and DeRozan has sat five. (That’s not to mention games missed by lineup mainstays like Derrick Jones Jr., Javonte Green and Coby White.) Things get uncomfortable for everyone else, and the players whose roles are stretched to account for absences show signs of wear and tear.

The Bulls have suddenly gone from first to fifth place in the East, and they’ll have to fight to avoid dropping into the play-in tournament. According to Tankathon.com, the Bulls have the league’s second-toughest remaining strength of schedule, as all six of their remaining games are against teams in position to either make the play-in tournament or the playoffs outright. The two teams with which they’re jockeying for position have the fifth-easiest (Raptors, tied with Chicago) and 13th-easiest (Cavaliers, two games back of Chicago) remaining schedules. The Bulls have the tiebreaker against both teams by virtue of having won the season series against each, but they’re cutting things pretty close at the moment.

And, of course, the Bulls have higher hopes than merely avoiding the play-in tournament. Earlier this season, they were considered a contender to possibly make the NBA Finals. Their path to reclaiming that status is uncertain, especially with Ball seemingly unlikely to return to the floor this season. His absence puts the spotlight on Caruso, Williams, Dosunmu and White, who all have to play larger-than-expected roles to account for what the Bulls are missing without their starting point guard.

Ball and Caruso started the season absolutely smothering opponents with their perimeter defense. It’s no surprise that with one or both of them out for all but three games since the team’s electric start through 25 games, the Bulls have been unable to defend at the same level. Through the team’s 29th game of the season — Dec. 20 against the Houston Rockets — Ball and Caruso missed just three games combined. During that time, the Bulls yielded an average of 47 drives per 100 possessions, according to Second Spectrum. With their two stud defensive guards missing 76 of 94 possible player-games since then, that average has risen to 52 drives per 100, with the Bulls also allowing 3.5 more points per 100 possessions on opponent trips that include a drive.

With Ball out, the Bulls need Dosunmu and/or Williams to help Caruso deter opponents from venturing into the paint. Bulls opponents have taken 29.7 percent of their shots this season within 3 feet of the rim, according to Basketball-Reference.com. That number has to come down considerably for the Bulls to regain their defensive form, and the effort has to start on the perimeter because nobody is all that afraid of Chicago’s rim protection. And that’s with good reason: Vučević ranks just 64th in conversion rate allowed out of the 108 players who’ve challenged three or more shots per game at the rim, per NBA Advanced Stats.

For the Bulls to make a deep playoff run, they’ll also need Williams to do more than merely help Caruso protect the first layer of defense. Roster limitations mean that he or Green must spare DeRozan from taking on the toughest defensive assignment among opposing forwards. Especially with Ball out, DeRozan has far too much offensive responsibility to be counted on to defend primary offensive threats — and he’s a minus defender to begin with. Williams was supposed to be that guy for the Bulls, but his injury and inconsistent play since returning raise doubts as to whether he can reach the level necessary for the Bulls to seriously contend this postseason.

Neither Dosunmu nor White has proven to be quite the same level of shooter as Ball, but with DeRozan and LaVine controlling the team’s half-court offense, the two other guards simply need to knock down the open looks they’re granted. White has done well from the outside after a very shaky start to the season following surgery to repair a torn labrum in his shoulder, but he’s also very hit-or-miss: He connected on 49 percent of his triples in February, but he’s sitting at just 34 percent in March. Dosunmu, as previously mentioned, has seen his shooting fall off a cliff. Caruso has been a slightly above-average 3-point shooter during his career, but on considerably lower volume.

Each of Chicago’s young (or young-ish, in the case of Caruso) perimeter players will be tested, both through the rest of the regular season and especially in the playoffs. And while the Bulls will obviously need DeRozan, LaVine and Vučević at the top of their games to do any real damage, that trio can’t do it alone. They’re going to need help on both ends of the floor, and for Caruso, Williams, Dosunmu and White to provide it.