Dr Positivity wrote:Doctor MJ wrote:Dr Positivity wrote:
I think it's hard to point to any stat other than Raw +/- that would put Tatum on Giannis level, and the difference between a +10 and +14 player seems vulnerable to noise in that regard.
Hmm, so let's get clear on a few things here:
Raw +/- is your total +/- when you're on the court. Here's how Tatum & Giannis look there:
Tatum +607
Giannis +361
This is a massive, massive difference, and all the more amazing given that their two teams have comparable records.
From there, it certainly makes sense to ask whether Tatum's edge holds up with a more sophisticated version of the stat like RAPM, and the answer is yes. Tatum leads the league in RAPM by nbashotcharts with a massive lead over Giannis.
So this is not a situation where where I'm simply pointing at On/Off and relying a lot on Off numbers (which are of course prone to small sample size concerns) to make some statement here. Tatum does look better based on this sort of data than Giannis this year by regression, and in terms of what it's meant On court over the course of the year, it's meant a lot.
To put it another way:
If these players were on team records that were in proportion to their On court numbers, Tatum would be on a team that was drastically higher than Giannis, and he WOULD have been getting MVP attention a lot time ago. What's propping Giannis up is how well the Bucks now do without him. That's only reason they are seen as "eh, similar team accomplishment" in the first place, which then leads people to say "And we know Giannis is better so, he must be getting less help than Tatum", but the data tells a clearly different story.
Doesn't mean Tatum's capable of more with everything on the line against the top competition in the playoffs.
Doesn't mean Tatum's been more valuable this season by these metrics than Giannis was when he was winning MVPs.
But if we're judging these players by actual impact this season, rather than by some combination of team record, see, box score production, and pre-existing assessment, it should not be easy for anyone to dismiss Tatum > Giannis.
Tatum has played like 30% more minutes than Giannis, so once that is taken into account the total +/- number you posted does not paint that much different a picture than their on/off of +14 vs +10. If someone wants to take a heavy games/minutes played viewpoint to argue Tatum>Giannis, I guess that's reasonable, but in terms of the games played impact I can't say i'm going to take it a lot into account that Tatum's +/- is better than Giannis when both are good in that area. Tatum's +/- is mostly better cause the Celtics are 4 points worse on offense when he doesn't play than the Bucks without Giannis (Bucks offense with Giannis is slightly better than Celtics with Tatum). That could have something to do with their play but it seems plausible to me that some teams are better made up to play without their star scorer more than others. In regards to nbashotchart, one season RAPM has always had issues, for example George Hill is currently first on their DRAPM, and Whiteside is 3rd on ORAPM. Tatum is 9th on DRAPM and Giannis is 97th, which I'm not sure is justified. RPM has the same issue where Tatum's DRPM is much higher than Giannis.
Re: Tatum's played a lot more. Doesn't really hurt the Tatum argument does it?
Re: In games played...Tatum still has the edge in OnCourt, On/Off, and RAPM.
Re: Tatum's mostly better because the team hurts more on offense when he's not in whereas the Bucks do pretty well. Indeed. Which is all the more reason why it's amazing the Bucks don't have a better record. People are getting fooled because the Bucks still have a shot at the #1 seed, but they are performing VASTLY worse than they did when Giannis won MVPs despite the fact that their 2nd best player now (Jrue) wasn't even on the team back then.
Re: one season RAPM has issues. Ah, let's be clear: When we say stuff like this, what we've always meant is that the regression can have noise to it. But in this case there's no reason to think that's an issue because the raw data is so clear cut.
(And let's note, since you're skeptical about one year RAPM, the same site also has a 3 and a 5 year model. In the 3-year model Tatum ranks 2nd in the league, in the 5-year, he ranks 5th. We're not actually talking about that much of anomaly right now - we're talking of a continued growth above something that was already quite significant but many were not noticing.)
On the other hand, I'm certainly not saying that this RAPM means that Giannis is literally a much worse player than he used to be in the sense that he's no longer capable of doing what he did before. What I'd say we're seeing from Giannis is the same thing we see from most veterans: Once the regular season offers them nothing more to prove, they take it less seriously even if they still make sure to get their stats.
And Giannis has been pretty clear about this when asked about concerns about this regular season:

Dr Positivity wrote:I find the +/- evidence more convincing if it's backed up logically why someone has such a high impact beyond boxscore, eg. Draymond Green's makes sense why the numbers wouldn't capture it. In the case of Tatum I'm not sure what he's doing that's supposed to make him such a non boxscore king unless people think he's the main driving force for their defense, which I don't think Celtics fans do.
So, I think you've learned the wrong lessons about box score & +/- then. It's not a thing where the box score captures everything from classical stars and is only useful to identify other players who also have impact. The reality is that the box score always misses a ton of what's happening out on the court, and so when we see players with outlier +/- numbers over considerable sample, it always makes sense to ask what's happening.
In terms of what Tatum's doing out there, I think in one way the answer is simple:
You're talking about a guy who's always performing well by these metrics on both sides of the ball. He's a volume scorer scoring on solid efficiency while being a perimeter guy - which basically always means he's adding extra value compared to a similarly stated big man on offense - and defensively he's very solid there too.
I say all this but to be clear: I didn't predict Tatum would stand out to the degree he is this season, and I've never been particularly enthralled with him and his scraggly facial hair. Nevertheless, the data is eye-opening and not to be dismissed lightly.
























