Thomas is having an incredible offensive season but being an MVP requires more
Isaiah Thomas is having an incredible season. He’s scoring 29.7 points per game on a startling 62.6% true shooting percentage. That’s absurd enough. Thomas is also adding an additional 15.5 points per game through his assists. In all, he’s responsible for 45.2 of the Celtics points per game in just 34.4 minutes per game. All of that is remarkable and it should come as no surprise that Thomas is leading the league in Offensive Box Plus-Minus (“OBPM”) with an estimated+9.8 points per 100 possessions impact. He’s also third in Real Plus-Minus’s offensive component with a +5.9 impact. Those gaudy numbers have lead some people to start tossing Thomas into the MVP conversation, or at the very least, suggesting that he might belong in that conversation.
Thomas is fun and exciting and a tremendous story. He’s 5’9″ and he’s, at worst, one of the top 5 offensive players in the league this year. That simply shouldn’t be possible, but Thomas has made it happen through sheer force of will. To top it off, Thomas has established himself as the league’s preeminent fourth quarter closer.
That’s all great stuff. Truly. If things were just a little different, it might be the sort of thing that could really catapult Thomas into being a legitimate MVP level star. Unfortunately, there is that whole other half of the game that isn’t offense.
Defense Matters
When evaluating a potential Isaiah Thomas MVP candidacy, you have to look at his overall impact. In that regard, Thomas comes up laughably short of the true best and most impactful players in the league. It comes down to one thing, really. Thomas is an absolutely horrific defensive player. He is simply too small to bother anyone when he is guarding them and they attempt to shoot over the top of him. He might as well not even be there. Beyond that, Thomas’s short wingspan doesn’t allow him to contribute much in the way of steals or blocked shots. He also is a non-factor on the glass, as you’d expect given his stature. Most of this is not really his fault. He’s making the most of what he’s been granted, but this is the Most Valuable Player award about which we’re talking. We’re not grading on a curve.
With Thomas on the floor, the Celtics are surrendering an apocalyptically bad 114.5 points per 100 possessions. That would be worst in the league by a significant margin over the entire season. When Thomas sits, the Celtics defend like the best team in the league, surrendering just 103.6 points per 100 possessions. Now, some of that is due to Thomas’s backups. The Celtics’ guard rotation outside of Thomas is full of very good to great defensive players in Avery Bradley and Marcus Smart. Even sophomore Terry Rozier is a toolsy defender who can make opponents work with his length and athleticism. As a result, reading too much into Thomas’s raw defensive on-off numbers would be more than a little unfair.
What about the box score? Amongst players with a significant amount of minutes, Thomas’s Defensive Box Plus-Minus is the absolute worst in the league. That’s right: Thomas is leading the league in OBPM, while putting up the league’s very worst DBPM amongst rotation players. But, maybe that, too, is unfair. Perhaps it’s the case that Isaiah Thomas does the “little things” on defense. Maybe he’s not a guy who gets the things that DBPM is really most influenced by, steals or blocks or defensive rebounds, in bunches, but maybe he moves his feet well, plays good positional defense, and gets deflections or other hustle plays on defense. Maybe he’s good at, say, ball denial.
We can take these things in turn. If Thomas were truly doing all of those little things, we would expect him to at least be able to drag his Real Plus-Minus away from his poor defensive box-score prior towards something like average. Instead, just like in DBPM, Thomas is absolutely dead last in the defensive component of Real Plus-Minus with a -4.4 points per 100 possession impact.
Looking at a brand new measure of defense, presented by Steve Shea over at the Basketball Analytics Book blog, Thomas similarly comes up lacking. Shea developed a metric, called Perimeter Defense Rating (“PDR”) using the NBA’s publicly available SportVU data to better evaluate perimeter defense. PDR’s results pass the initial smell test with a top 5 that goes as follows: Tony Allen, Chris Paul, Draymond Green, Thabo Sefolosha, and Rondae Hollis-Jefferson. All five of those guys have a reputation for being very good to great perimeter defenders. Of the 184 players in the sample Shea provided (players with over 800 minutes played this year), Thomas grades out 132nd. That is, um, not great. It’s even worse when you consider that many of those players who graded out worse than Thomas as perimeter defenders are simply big men who don’t guard the perimeter very often.
Every defensive indicator for the Celtics is better with Thomas on the bench than when he is on the floor. Let’s look at the Celtics’ opponents shot distribution when he is on the floor versus when he’s on the bench. Shot distribution is a better indicator of the quality of defense played than, say, simply looking at field goal percentages on versus off, because shooting percentages in small samples are noisy. (Note, though, that the Celtics’ opponents do shoot better from every area of the floor when Thomas is on the floor).
As you can see, with Thomas on the floor, the Celtics surrender many more dunks and layups and force many fewer midrange shots. Boston surrenders the same percentage of opponent shots as 3 pointers with Thomas on versus off, but opponents convert 3 pointers at 36.6% with Thomas on the floor versus just 30.4% with him off. That’s probably mostly statistical noise. So, we shouldn’t hold it against him much. His presence resulting in Boston surrendering a much less favorable shot profile, however, we can probably hold against him.
Beyond the shot profile, the Celtics get creamed on the defensive glass with Thomas on the floor versus off, according to NBA.com. They also surrender a greater free throw rate and turn their opponents over less frequently when Thomas plays versus when he sits.
Any way you slice it, Thomas is a huge negative for the Celtics on defense. “Traffic cone” is not an unfair characterization of his defense. It is to Thomas’s immense credit that he is able to overcome his massive defensive shortcomings to still be a player with a positive impact. It takes an absolutely Herculean offensive impact to counterbalance defense this bad. That makes him a fun player and a joy to watch, but it doesn’t make him an MVP candidate. There are simply far too many players that impact the game on both ends or impact the offensive end as much as Thomas or close to it, without cratering their teams’ defenses to even think about putting him in that conversation.
Resist the Narrative
The pushers of narrative have suggested and will continue to suggest that Thomas’s role as the “star” and primary scorer and closer on a Celtics team that is second in the East is enough to put him “in the MVP conversation.” There are a few problems with this.
The East is Weak at the Top
Second in the East isn’t really that impressive. The East is not a top-heavy conference, it is mostly a morass of teams with the Cavaliers being easily the most talented team and a bunch of also-rans. The real competition in the NBA lies out West. There are no less than 5 teams in the West that are better than the Celtics, by Simple Rating System, which is simply margin of victory adjusted for competition. Those teams are the Warriors, Spurs, Rockets, Jazz, and Clippers. Additionally, the Toronto Raptors are in a virtual tie with the Celtics on record and look to be the better team according to SRS.
Giving the “Star” All the Credit
To put Thomas in the MVP conversation, despite his defensive warts, because he’s the “best” player on a pretty good team, which is to say, the best offensive player, would be to repeat a mistake that voters made with Derrick Rose in 2011, only moreso. In 2011, at least Derrick Rose was the lead guard and driving force behind a team that won the most games in the league. Even granting that, however, the Bulls won with grinding defense that worked in tandem with Rose’s special talents.
Unlike those Bulls, the Celtics do not win with their defense. In fact, they have a bottom 10 defense, largely due to how bad they are when Thomas is on the floor. They do, however, have a very deep and talented team and to act as if Isaiah Thomas is dragging the Celtics to their status as a pretty good team is to misallocate the credit. Al Horford, Jae Crowder, Amir Johnson, Kelly Olynyk, Marcus Smart, and Avery Bradley can all be counted as players that make a positive impact for Boston. Thomas is no one man band. We shouldn’t pretend like he is for the sake of a fun MVP narrative.
All the Other Deserving Candidates
The NBA is lousy with talent right now. It’s one of the deepest periods ever. As a result, there are simply a ton of guys who deserve consideration over a guy who is arguably the worst defensive player in the league. Quickly, James Harden, Russell Westbrook, Kawhi Leonard, LeBron James, Kevin Durant, Kyle Lowry, Stephen Curry, Giannis Antetokounmpo, Jimmy Butler, and John Wall all have far stronger MVP cases than Isaiah Thomas, and that is hardly an exhaustive list.
Isaiah Thomas is having a career year. He’s got one of the most telegenic games in the league. But he’s no MVP. Stop this nonsense.
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