Note: These two separate moves are being grouped together for one set of trade grades.
Mavericks get: Willie Cauley-Stein, Justin Patton
Thunder get: Isaiah Roby, cash
Warriors get: Utah's 2020 second-round pick
Get more trade grades for every deal here
Dallas Mavericks: A-
As soon as Dwight Powell collapsed while driving to the basket Tuesday night, it seemed clear that Powell had ruptured his right Achilles, ending his season. Prior to the injury, Zach Lowe's 10 Things column last week helped capture Powell's value to the league's best offense as a premier above-the-rim threat out of the pick-and-roll.
Because Kristaps Porzingis can slide down to center, the Mavericks aren't desperate for help in the middle. Their offense was as potent as ever Thursday in Portland, where Dallas made 22 3-pointers in a 133-125 win over the Blazers. But given backup center Boban Marjanovic -- who did not play Thursday -- has a tough time staying on the court against quicker opponents (I'd say "smaller" but every opponent is smaller for the 7-foot-4 Marjanovic), the Mavericks could use another option -- particularly someone who could fill Powell's role as a rim runner.
Enter Cauley-Stein, another above-the-rim finisher with enough athleticism to defend either frontcourt spot if Dallas wants Porzingis to defend centers. The two players aren't perfect matches. Cauley-Stein hasn't been as efficient a pick-and-roll player as Powell, though he also hasn't been in as favorable of a situation as he will be now with Luka Doncic as a ball handler and multiple shooters to space the floor.
So far this season, pick-and-rolls that have resulted in Cauley-Stein shots have yielded 1.29 points per chance, according to Second Spectrum tracking, putting him 23rd among the 69 players with at least 50 such shots. By contrast, Powell's 1.48 points per chance on pick-and-roll finishes ranked fourth in this group. Powell also offered some nominal floor spacing, having made 10 3-pointers this season (at a weak 26% clip) after a career-high 39 in 2018-19. Cauley-Stein has made just four triples in his five-year career.
At the other end, however, Cauley-Stein might prove an upgrade as a better rim protector than Powell. The 52% opponents have shot inside 5 feet with Cauley-Stein as the nearest defender ranks 14th among players who have defended at least four such shots per game, via Second Spectrum tracking on NBA Advanced Stats. Powell was 37th of this group, with opponents shooting 59% inside 5 feet.
For a Mavericks team with legitimate aspirations of winning a playoff series for the first time since the 2011 championship, giving up little in the way of draft compensation (Utah's second-round pick currently would land 57th overall) for Cauley-Stein is an easy call.
Dallas also might not yet be done dealing, having retained a 2020 second-round pick of greater value, which came from Golden State in the long-ago Andrew Bogut deal and is sure to land near the top of the round. The Mavericks also still have $9.8 million of their trade exception from the Harrison Barnes deal, which expires the day after the deadline, after using $2 million of it on Cauley-Stein's salary. The $12.8 million expiring contract of Courtney Lee would give them even greater purchasing power in trade.
The most curious aspect of this deal is why Dallas chose to trade Roby rather than waive wing Ryan Broekhoff, who had played just 77 minutes all season before suffering an injury to his left fibula that has him sidelined. Broekhoff did play well enough as a rookie for the Mavericks to guarantee his 2019-20 salary, making 41% of his 93 attempts from 3-point range, and it's also possible they simply wanted to get off Roby's $1.5 million guaranteed salary for 2020-21 -- particularly with the possibility that Cauley-Stein picks up his $2.3 million player option for next season.
After drafting Roby with the 45th overall pick last June, Dallas gave him a contract similar to a late first-round pick with guaranteed salaries of approximately $1.5 million the first two seasons and non-guaranteed minimum salaries the next two. Remarkably, Roby is making more this season than any other 2019 second-round pick.
In that context, it's noteworthy that Roby has yet to see any NBA action. A battle with plantar fasciitis limited Roby to nine G League games, during which his numbers (15.8 points and 12.0 rebounds per 36 minutes) were unspectacular. So perhaps the Mavericks felt buyer's remorse with Roby and his contract.
Golden State Warriors: A-
The Warriors signed Cauley-Stein last summer for a season that effectively ended with Stephen Curry's second metacarpal fracture in Cauley-Stein's Bay Area debut. Though Cauley-Stein has started 37 games, he didn't necessarily factor into Golden State's long-term planning. Backup Omari Spellman, under contract for 2020-21 and four years younger, is a more likely part of the Warriors' future. So perhaps, too, is Marquese Chriss, who's on a two-way contract but has averaged 17.6 minutes per game for Golden State this season.
Simply moving Cauley-Stein's salary was a positive for the Warriors because of the hard cap at the luxury-tax apron imposed on them this season after the sign-and-trade deal for D'Angelo Russell. Shedding Cauley-Stein's $2.2 million gives Golden State more than enough room under the apron to convert the two-way contracts of both Chriss and guard Ky Bowman, whose NBA service time was running out. I wouldn't be surprised if both players get multiyear deals along the lines of the one the Warriors gave wing Damion Lee when they converted his two-way contract earlier this month.
For Golden State to get a second-round pick in the deal, even one at the end of the round, makes this a clear win.
Oklahoma City Thunder: B
From the Thunder's standpoint, giving up just cash to upgrade from Patton to Roby as a project at the back end of the roster seems like a solid piece of business. Oklahoma City had signed Patton as a free agent before training camp, and he spent most of the season with the Thunder's G League affiliate, averaging 15.7 points, 10.7 rebounds and 4.3 assists per 36 minutes.
As noted by ESPN's Bobby Marks, a small benefit to this deal is Oklahoma City shaves about $300,000 off its luxury-tax bill because Patton's $1.6 million salary is ever so slightly higher than Roby's. However, the odds are good that the Thunder will find a way out of the tax entirely by dealing a minimum-salary player at the deadline, so the difference is unlikely to ultimately matter.