NBA
Shelvin Mack: Utah Jazz’s Catalyst

In chemistry, the word βcatalystβ is defined as βa substance that increases the rate of a chemical reaction without itself undergoing any permanent change.β Without altering its own characteristics, a catalyst makes life easier, so to speak, for other elements of a chemical reaction.
Utahβs Shelvin Mack doesnβt quite qualify by the strictest scientific definition. Certain elements of his game since arriving in Salt Lake City at the deadline have unquestionably changed or improved, and his role has expanded rapidly. His basic numbers reflect as much, showcasing the degree to which heβs seized the ample opportunity afforded him.
But despite his personal progress, viewing Mack as a true scientific catalyst for this Jazz team might be the best, and maybe only, relevant way of parsing out his impact.
This isnβt the same Shelvin Mack from Atlanta, at least not in a couple pretty vital areas. Shooting from the point guard position was an area of need in Utah at deadline time, and at first glance Mack appeared to offer nothing of the sort. At just 15 percent from three in Atlanta along with a sub-33 percent career mark, things started off badly in his new home as well β Mack was at just 30 percent from deep through his first nine games in a Jazz uniform.
The sample remains pretty tiny, but Mack has flipped that script on its head since. Heβs shooting a nearly unfathomable 56.3 percent from beyond the arc over the last eight games, bringing his overall percentage with Utah all the way to a hair under 46 percent, best on the team. His career sample obviously makes it virtually impossible heβll continue as a mid-40s guy from deep, but it seems fair to expect a capable jump shooter moving forward.
His personal comfort level flipped a switch somewhere in there, perhaps in a strong performance against John Wall and the Wizards; Mack himself said afterward that his adjustment to both his surroundings and Utahβs altitude was finally reaching a comfortable place. Very different teammates stylistically contributed in large part to a learning curve.
βFor the past four years, Iβve been playing with mostly pick-and-pop bigs,β Mack said. The adjustment away from Paul Millsap and Al Horford types took time. βFavs [Derrick Favors] and Gobert, thatβs not [really] their strength.β
Mack is assisting on easily the highest percentage of teammate baskets in his career, and drawing more free throw attempts than ever before. His percentage of possessions used while on the floor has skyrocketed. On the flip side, his turnovers have risen (as expected) with a 20 per-100-possession rate that remains a tad out of control even as Mack has started to rein things in a bit recently.
Mackβs true value only begins to take shape, though, when one zooms out and looks at the way his presence has galvanized his new surroundings.
The Jazz are outscoring opponents by 6.0 points per-100-possessions with Mack on the floor since his arrival, easily a team-best figure in that time and one that would rank among the leagueβs top five teams on the season. Heβs part of a starting lineup thatβs thrashing opponents to the tune of a plus-11.1 per-100 in that time, sixth-best of any five man unit in the NBA thatβs logged over 100 minutes since the break. The sample is only growing.
Some areas of improvement are easy to understand, particularly on the defensive end. Mack immediately became Utahβs quickest guard and best option for defending at the point of attack, with a bit more bulk than Raul Neto or Trey Burke β allowing him to switch more often, a Quin Snyder staple on the perimeter. Quick hands combined with quick feet allow him to generate turnovers other Jazz guards arenβt capable of engineering, particularly when opponents unaware of his closing speed and reflexes think theyβre clear of him.
Opponents are turning the ball over nearly 20 percent of the time when Mack is the primary defender in pick-and-roll situations, per Synergy Sports, among the top quarter for qualified guards in the league. Again, though, the true value is more easily demonstrated in team numbers here than Mackβs own individual stats β the Jazz have generated more opponent turnovers with Mack on the floor than any other player since his arrival, forcingΒ over two extra cough-ups per-100-possessions when he plays compared with when he sits.
Items around the margins are tougher to attribute directly to Mack, but he seems to keep popping up in positive areas. Opponents attempt fewer per-minute shots and free throws with Mack on the floor than any other Jazz player, likely due to some combination of the turnovers, his above average rebounding for a guard and some amount of randomness. Utah’s opposition draws nearly five more fouls per-100 when Mack sits down, and shoots a much lower percentage from deep while heβs on the court. While thereβs plenty of noise attached to these numbers, thereβs a point at which a guy showing up so positively in enough areas is a clear indication that something is going right while heβs on the floor.
Itβs much of the same on offense β good things are clearly happening while Mack plays, but the underlying reasons can be tougher to place. All relevant team shooting numbers plummet when he leaves the court, in part due to his own recent accuracy, but thereβs more at play here.
Nearly every primary Jazz player shoots more efficiently when Mack plays next to them, especially the other perimeter players: Gordon Hayward (42 percent from three with Mack, 30.3 percent without him since the trade), Rodney Hood (38.5 percent with, 25 percent without), Joe Ingles (45 percent with, 29.2 percent without) and even rookie stretch big Trey Lyles (47.4 percent with, 21.4 percent without) all show remarkable upticks in accuracy while alongside Mack, per nbawowy.com prior to Wednesday night’s games.
Exactly why this is happening is open to interpretation, though simple variance certainly plays a role with a sample this relatively small.
Mackβs prowess as a passer is near the top of the list; he has elements of creativity to his game that Neto and Burke both lack. His timing is better, as is his feel for the defense heβs baiting. Heβs generating more potential assists than any other Jazzman at over 10 a game, creating nearly 14 points nightly through his assists alone, per SportVU data. Utahβs other point guards lack either the burst, the passing skill or both to make some of these plays.
Snyder has talked frequently about Mackβs tempo since his arrival, and the numbers make it clear Quin is referring to a style of play rather than the βpaceβ element many tend to think of first. The Jazz are still among the slowest teams in the league by possession since Mackβs arrival, and his own presence on the court has actually slowed things down even further in this regard.
Thatβs not really what Snyder means, though. Heβs talking more about the way Mack plays; the speed with which he arrives at his spots and makes his decisions. To some degree, this is the element of team success while Mack is on the floor thatβs been tougher to dissect β how does one quantify things like feel outside actual assists? Maybe Mackβs passes find their exact targets more accurately, and allow for a smoother shooting motion. Maybe his teammates find some subconscious comfort in the pace of his game. Maybe his ability to use a higher portion of team possessions while on the floor has trickled down to everyone else on the court (this is likely, though to what degree we canβt really know).
Whatever it is, thereβs something here that all our fancy stats donβt fully account for. No combination of figures, individual or team, quite covers the startling gap between when Mack plays and when he doesnβt.
The easiest reasoning is simple: Heβs much better than the other guys Utah has at his position. Itβs not untrue. Again, though, one delving deeply into the causes of his success canβt help but notice that his individual advantage in a vacuum doesn’t come all that close to accounting for how much better the team has been.
Whether the results can sustain β or are good for the long-term future of the core β is another question, with murkier answers. Certain parts of the success simply canβt continue at this rate – Mackβs own ridiculous rate from three in recent weeks among them. Perhaps more notably, Mackβs presence has cut down the touch time for guys like Hayward and Hood, generally considered the teamβs offensive focal points. Itβs fair to wonder if Snyderβs reliance on Mack sometimes comes at their expense, though itβs tough to argue with the results recently; if the chips fall differently and depriving the top guys of their command on the offense turns into a problem, it could end up a slightly different conversation.
Weβre not there yet, though, and those concerns get tougher to stick with as the franchiseβs first playoff berth in four years gets clearer at the end of the tunnel with Mack among the driving forces.
Maybe heβs just one of those tricks your high school chemistry teacher would never reveal to the class. Shelvin Mack has become Utahβs catalyst for success as they push for a playoff berth, and even if it’s tough to capture empirically, that wonβt stop anyone from marveling.