Iman Shumpert's 2015-2016 has not gone very well. He started the season sidelined with a strange preseason injury after rupturing a wrist extensor tendon during a dunk, and since he returned from that injury in mid-December, he's struggled to find his shot. Statistically, he's having the worst offensive season of his career, fielding career lows in shooting percentage (37.7 percent), three-point percentage (30.3 percent), and points per game (5.8). He's only shooting 32 percent on catch-and-shoot threes, and that number has been a dismal 25 percent over the past 10 games. Something clearly is not right with Shumpert's shooting.
But despite the season-long struggles for Shumpert, the Cavs have recently been much, much better with Shumpert on the floor. The Cavs have played well recently, going 8-3 in their last 11 games, and Shumpert has the second largest net rating differential on the team during that stretch. The Cavs are +12.4 per 100 possessions when Shumpert is on the floor, and -4.2 when he sits since February 29th. Only Jordan McRae (whose net differential showcases the Cavs' weirdly dominant play in garbage time as of late) has a better differential than Shump over that time. It's not a surprise that Shumpert's ratings are higher than guys like LeBron James and Kyrie Irving, who play with a wide array of lineups. But that he has a bigger impact than Channing Frye and Tristan Thompson, who have been brilliant of late, is a surprise.
It would be one thing if Shumpert was rounding into form offensively. But he's actually been about the same, upping his field goal percentage to 39.5 percent but shooting 29.2 percent from three in the month of March. He's also posted a usage rate of just 9.6 percent over the last month, which is a very low number for a rotation player. The numbers don't show that Shumpert's making a big impact on the defensive end, either, because while the team has been better on that end with him on the floor (102.4 DRtg vs. 111.2 with him off), he's struggled per SportVU defensive metrics, allowing opponents to shoot 48.8 percent against him from the field and a very concerning 43.2 percent from three since February 29.
So why are the Cavs so good with Shump on the floor, even if he's struggling? Part of it is influenced by who he's playing with, obviously. Shump has spent over 170 of his 269 March minutes with Tristan Thompson and/or Kyrie Irving on the floor, and Irving/Thompson lineups have a net rating of +14.6 over that span. As David Zavac pointed out recently, bench-heavy units led by Kyrie Irving have been awesome recently, and those account for 39.8 percent of Shump's minutes during that span, per NBAwowy. Shumpert also has spent just 37 minutes playing with Timofey Mozgov during that time, which also is a factor because lineups with Mozgov have been a horrendous -14.5 per 100 possessions since February 29. So, it's reasonable to assume that Shump's numbers are partially inflated due to the impact of who he is (and possibly more importantly, isn't) playing with.
However, that's not the entire story with Shumpert. As we've learned from Mozgov this season, it's hard for a player to play terribly and maintain a positive lineup impact. And while Shump has had defensive struggles and his shot is still broken, he's found a major way to contribute. He's still averaging 3.6 assists per 36 minutes in March, and he's been surprisingly effective as a secondary distributor over this period. Teammates are shooting 54.5 percent from three off of Shumpert passes over the last 11 games, per SportVU passing data, and Irving has shot 62.5 percent from the field off of Shumpert passes in that span. He's gotten nearly a full assist opportunity more per game over this span, and these numbers suggest that Shump has been a key factor in the success of Irving-led bench units. He's also been a better rebounder as of late, averaging 5.1 rebounds per game in March.
Shumpert is in Cleveland to be a three-and-D wing, but he's struggled at both the three and the defense this season. However, over the past month, his role appears to be morphing to compensate, as he's getting more chances to set teammates up and crashing the glass to compensate for his recovering shooting mechanics and rusty defense. Both of those things are still major problems, and looking forward to the playoffs, the Cavs need Shump to be a little more on his game on one or both ends to justify playing time. However, he's proven recently that he can contribute to positive team play even if he's not having individual success, and he's likely far less of a problem than Mozgov when it comes to playoff outlook.