Post#13 » by DraymondGold » Mon Aug 11, 2025 5:05 pm
Cool stuff! I agree with the earlier statements that this is interesting, and worth doing to see how it compares to the RS-only or full-season versions... but that this is one of the less informative RAPMs made by Engelmann. No offense meant to Engelmann -- he's one of the great NBA statisticians, and I'm glad he made this RAPM -- but I want to caution over interpreting this relative to his prior RAPMs.
Limitations:
1) Full-career RAPM vs single/several-season RAPM: Doing a full-data RAPM (1997-2024) without any aging curve or anything of the sort treats these players as constant over their full career... over such a long timespan like this (over 25 seasons!) is obviously a faulty assumption. 2006 LeBron is a different player from 2016 LeBron. 2006 Kobe is a different player from 2016 Kobe. Treating the players as the same over their full career makes it far less clear what signal actually comes out at the end. Some sort of possession-weighted estimate of the players' average value?
Now, in regular season or full-season data, we have enough randomly sampled games between so many lineups and opponents that we probably get a reasonably accurate (albeit high uncertainty) version of the average value of a player. But that's far less true in playoff-only data.
2) Lack of sufficient playoff samples: A) Star players play more minutes, so the off-minutes and off-lineups are limited for them. B) Teams don't always make the playoffs, giving us a far reduced uneven sampling of their playoffs. Consider two players who are equal in value across age, and get worse as they get older. If one player gets older and their team misses the playoffs while another player gets older and their team makes the playoffs, we'd likely see the first player as rated better in this metric... when it's simply because they happened to make the playoffs, not because they're actually better. C) The lineups played and faced are not evenly or randomly sampled. Teams only face a few opponents each year at most. Worse still, there's only a single team each year that plays each other across conferences. This is far from the ideal case where each player and each lineup gets enough time against each other player and each other lineup that the we have a sufficient sample to calculate a fair RAPM. With no RS data used or RS prior, this limitation C seems particularly crippling to the accuracy of this exercise.
3) Lack of error bars given: the best full-career RAPMs give error bars, which are pretty crucial to interpreting how much better one player is from another. We don't have error bars here, unlike some other versions of full-career RAPM.
So it's an interesting exercise. It's definitely worth doing, as having a truly accurate and stable playoff RAPM would be one of the most useful stats when evaluating a player. But I fear the limitations are exacerbated by being playoff-only without any RS data whatsoever (particularly 2c), which undermines some of the usefulness.
The top tier of players are probably some of the most valuable playoff performers -- so this is nice evidence to support the playoff value of LeBron, Draymond, Manu, Duncan, Durant, and Curry. Likewise, if a player here is ranked especially different from expectations or from their RS-only full-career RAPM, that might be informative (or at a minimum, worth considering whether one of the limitations above applies to that player). But I would definitely hesitate to trust the exact ordering, even moreso without knowing the uncertainty bars.
Re: Draymond vs Curry, here's the raw plus minus data from pbpstats.com from the years they both made the playoffs:
13-25 Playoff Draymond:
On: +973 = +8.3 per 100
Off: -146 = -3.0 per 100
On-Off: +11.3 per 100
13-25 Playoff Curry:
On: +954 = +8.3 per 100
Off: -145 = -3.0 per 100
On-Off: +11.3 per 100
So if we don't filter for just the games they both played, they end up looking nearly identical in both On and On-Off. And given how close they are, it's not crazy for one of them to sneak ahead. But what if we just look at their plus minus profile in the games they both played?
13-25 Playoff Draymond (games Curry/Draymond both played):
On: +861 = +8.1 per 100
Off: -107 = -2.5 per 100
On-Off: +10.6 per 100
13-25 Playoff Curry (games Curry/Draymond both played):
On: +954 = +8.2 per 100
Off: -200 = -6.1 per 100
On-Off: +14.3 per 100
Suddenly Curry looks like the clear highest impact player for the Warriors, with a tiny advantage in On rating and a clear advantage in On-Off (which correlates slightly more strongly with RAPM than On). So as DoctorMJ said, Draymond got to strengthen his playoff data against easier first-round opponents... while Curry's missed games cause his sample to be biased low, as he only faced harder opponents.
This kind of biased sample seems like exactly the kind of thing a PS-only RAPM would struggle to capture. For first-round-exit teams, we lack any regular season data or prior, which might be used accurately measure that the first-round exit teams are worse than the late-playoffs teams. Worse yet, if these first-round exit teams are perennially first-round exit teams or occasionally missing the playoffs, then the sample size overall for them is relatively smaller, and again a playoff-only full-career RAPM doesn't gain as much information on them to see that they're easier opponents for the Draymond-only Warriors.
To be clear, I agree with others than Draymond is highly underrated by the casual fan, and one of the true high-impact playoff players of the modern era. As the second to third most valuable player on the most dominant dynasty of the era, we would expect him to be one of the most valuable players of the era.
(Note by value here, I mean value in their specific role... which some might argue was particularly suited or particularly favorable for Draymond relative to there rest of the top tier of players, or that Draymond's impact is more dependent on playing this role and less versatile relative to the rest of the top tier of players here ).
Draymond is arguably the best defender of this era (I would say he is), and was a clear positive on offense in the role he played for much of his playoff career. His chemistry with Curry and Klay was one of the key parts of the Warriors' success. It's seriously impressive that a Draymond-reliant Warriors could perform well in the first round without Curry.
But I don't think this is compelling evidence to think Draymond was more valuable to the playoff Warriors than Curry was over the course of their careers. I think the sample is just being biased here by the easier first-round opponents and the easier schedule that Draymond faced, which is exactly the kind of thing a playoff-only RAPM would miss if it ignores all regular season data.