2016 RAPM/RPM/etc. *Full 2016 RS + PS RPM & RAPM Updated 6/24*

[ceiling raiser]

Davis and Harden...damn.

[Dr Spaceman]

So is Patty Mills the 6MOY front runner then?

I actually had him 3rd on my 6MOY ballot last season, but no, Ginobili has been clearly more impressive this season. Manu has been the Spurs 2nd best offensive player after Kawhi. Mills has a small edge in single year RAPM- a stat that's dominated by collinearity in samples like this. I've pointed out before that Mills' insane impact has to be qualified by the fact that he's a poor ball handler and thus always shares the floor with either Manu or Diaw, and usually both. I think what we're likely seeing here is that he plays all minutes with Manu- a ridiculously good pairing that makes them both look awesome, but then Manu plays far more minutes with other lineups that drag his numbers down a fair bit relative to Patty. And even then Mills has only a slight lead.

EDIT: actually perhaps I spoke too soon. Ginobili has played 73% of his minutes while Mills has only played 59% with Ginobili. This is interesting, especially as lineups with only Ginobili seem to be outperforming lineups with only Mills. But I suppose it's possible Mills has actually been better.

[Quotatious]

Davis and Harden...damn.

173rd and 294th, respectively...If I've ever seen a player who puts up "empty numbers", Davis and Harden are the epitome of that phrase, this season...

Wade looks really bad, too (328th).

That thing with three GSW guys at the top is pretty amazing...That's what happens when you play on a team that almost never loses a game, though. It was the same with Jordan, Pippen and Kukoc being the top 3 in 1995-96 raw plus minus (that you took from Pollack's book )

[Dr Spaceman]

Davis and Harden...damn.

Yeah this isn't good. Davis has truthfully never looks great by impact stats but this is another thing.

Harden IIRC was the leader in NPI for almost all of last season until Green overtook him toward the very end. It's really troubling (but not that surprising) to see his offense hasn't even been good this year. And that defense... Ugggggghhhhh.

Aside: people have been railing for a while about the inclusion of the box score in metrics like xRAPM and RPM, and while I've agreed in spirit, it's never been so clear to me as now when I see Harden like 12th in RPM and like 260th in RAPM. That's not right.

[MyUniBroDavis]

Davis and Harden...damn.

Yeah this isn't good. Davis has truthfully never looks great by impact stats but this is another thing.

Harden IIRC was the leader in NPI for almost all of last season until Green overtook him toward the very end. It's really troubling (but not that surprising) to see his offense hasn't even been good this year. And that defense... Ugggggghhhhh.

Aside: people have been railing for a while about the inclusion of the box score in metrics like xRAPM and RPM, and while I've agreed in spirit, it's never been so clear to me as now when I see Harden like 12th in RPM and like 260th in RAPM. That's not right.

A lot of it has been situational.

It's lineup adjusted right?

With Davis out, that basically means Anderson is the go to scorer.

The thing about Davis this year has been gentry wanting him to pick and pop and back down instead of roll to the basket and faceup. The result is Davis being absolutely abysmal is isolations, post ups, and mediocre in pick and rolls. Essentially, he is taking away from ad his quickness, speed, handles which are very good for his size, ability to finish through contact, etc.

And Anderson is hitting 53% of his mid range jumpers with AD, so it's not a spacing thing.

With ad off the floor, Anderson, who is one of the most efficient post players in the league, scores 23.5 per 36

His defense has actually improved tremendously from last year in my opinion. with him on the court teams shoot 47.5% from inside the arc, which would be top 10 in the league, compared to teams shooting 51.6% with him off it (his replacement is usually asik)

The problem is, teams shoot ridiculous percentages on 3s against the Pelicans, who contest the shot about at a league average rate in terms of % of contested 3s took.

Davis guards 3 3s a game and teams shoot 28% on those 3s against him, and he is a top 10 player in defending the spot up.

Yet with him on the floor, teams are shooting nearly 38% from 3 despite him contesting them at an excellent rate.

I mean, looking at his offense and defense as a whole, both are about the same, his defense improving slightly possibly, aside from the fact that gentry basically took away his faceup game and ability to roll to the basket. All so Davis can shoot mid range jumpers.

(On a sidenote, these same changes are what led ad to turning it. Over so much. Iirc, his turnover stats per play is better this year than last year in everything except isos and post ups)

I agree that his impact has been minimal, this isn't me trying to say something like "no my favorite player is shown badly by this stat so it must be wrong!"

But I think that how he plays and his impact haven't really mixed. impact is fit + utilization + ability right? That's something along the lines of what trex said late in the project. I'd say that coincidence applies too, and AD, on an impact basis, has had horrible "coincidence"


Is there any reason why curry ranks so,low on offense? I'd think he is better than a 5+, or does that go up with possessions?

Oh, and rapm is essentially lineup adjustments right?

[NinjaSheppard]

Really nice to see DJ develop into the best defensive player in the game

[PCProductions]

Really nice to see DJ develop into the best defensive player in the game

I'll admit that this test case really turned me off of RPM entirely.

[lorak]

So first of all, DJ isn't "the best defensive player in the game" according to DRPM. Duncan is. Jordan is second alongside with Bogut and Green. And while DeAndre's defensive impact might be overrated (because of box score component) he is still the best defender on -2.1 DRTG team. His defensive on/off is second among all Clippers players (Johnson is first) and he looks quite good in defending the rim (he is at Duncan's level), while opp eFG% is LAC biggest defensive strength. So if anything DRPM shows how player like DJ could improve on defensive end - what in no doubt he did under Doc Rivers.

[Hawk]

Could someone make me a ELI5 (Explain Like I'm 5) on RAPM and RPM¿?

Thanks

[cpower]

I dont trust any stats that put Monta Ellis over Anthony Davis.

[MyUniBroDavis]

I dont trust any stats that put Monta Ellis over Anthony Davis.

On a pure impact basis it's understandable why Davis ranks so low.

His offense is not being used right

And his defense, which started out well, has progressively gotten worse as the season goes on.

[cpower]

I dont trust any stats that put Monta Ellis over Anthony Davis.

On a pure impact basis it's understandable why Davis ranks so low.

His offense is not being used right

And his defense, which started out well, has progressively gotten worse as the season goes on.

well, still way better than someone doesn't know how to play offense and defense at all.

[SideshowBob]

Could someone make me a ELI5 (Explain Like I'm 5) on RAPM and RPM¿?

Thanks

How about an ELI10?

[#1]APM is Simple OLS, exactly as Spaceman described it. Set up every 5on5 matchup, set equal to the scoring margin and solve for each player across the league (I've run it for a few years, its like ~65000 lines of 5on5 matchups). The resulting coefficients (on each player) are the APM values. This needs a very large sample size to say anything of considerable meaning; a single-year APM has large error terms on each coefficient, multi-year (usually 2-year) studies are preferred.

RAPM is essentially the same thing (OLS) with one exception. It introduces what we'll call a "reference matrix", basically each player is given a baseline value, towards which their coefficient will be pulled. I believe this tries to reduce the multicollinearity problem.

In [#2A]vanilla/basic RAPM, every value in the reference matrix is set to 0. The greater the amount of games played, the less weight that reference of 0 has. It is almost the same as APM [#1], but the regression towards 0 in theory reduces the error within a single-season set. It's still fairly volatile, but it's better than APM [#1] is within a single year. There is also [#2B]multi-year RAPM, which just uses a larger number of seasons, with most weight given to the current year and less and less weight given to previous years, reference matrix of 0s.

[#3]Prior-informed RAPM is essentially the best (ITO out-of-sample prediction) version of this family without introducing the box-score. It's built the same way as RAPM, but the reference matrix uses RAPM values from the previous year, instead of all players being set at 0. Again, as the sample size of the season grows, the reference value holds less and less weight. Obviously this only works once we have multiple years of data, in the 1st year, there is no prior. In the 2nd, we have a prior but it is vanilla RAPM [#2A], but by the 3rd year we can use PI RAPM of the previous year to inform the current year.

[#4A]RPM is RAPM, but the reference matrix is made up of SPM values (SPM is again, regression of box-score metrics on a multi-year non-box-score model such as RAPM). There is also [#4B]multi-year RPM, which is the same as multi-year RAPM, except it presumably uses a reference matrix of multi-year SPM values.

There is also [#5]prior informed RPM. Again, same idea as PI RAPM [#3], single-year, reference matrix of prior-year's RPM values.

I don't want to open the can of worms that is the financial collapse, but as far as I understand, it's more along the lines of knowingly turning a blind-eye to what were known as poor models, rather than them just being present/utilized.

ESPN, is unfortunately poor at labeling and differentiating between what they put up on their site. Luckily for us, JE, one of the co-creators, often posts on APBRmetrics and has offered clarification.

ESPN's site has RPM for three seasons, 2014, 2015, 2016.

2014 is multi-year RPM [#4B]
2015 is single-year RPM [#4A]
2016 is single-year RPM [#4A]

It's silly, but they've given us 2 different models for 3 years and labelled them all the same.

Multi-year RPM [#4B] for 2015 was provided in an article last year before the playoffs. Other than that, everything they've posted is single-year. I asked Engelmann for multi-year RPM for this year on twitter, and he said that it was in the works. Where it will be posted I can't say, but I'm sure he'll clarify at some point.

[lorak]

I dont trust any stats that put Monta Ellis over Anthony Davis.

Monta 0.0 RPM
Davis +2.7 RPM

[cpower]

I dont trust any stats that put Monta Ellis over Anthony Davis.

Monta 0.0 RPM
Davis +2.7 RPM

was referring to multi-year RAPM

[The-Power]

I dont trust any stats that put Monta Ellis over Anthony Davis.

On a pure impact basis it's understandable why Davis ranks so low.

His offense is not being used right

And his defense, which started out well, has progressively gotten worse as the season goes on.

well, still way better than someone doesn't know how to play offense and defense at all.

RAPM isn't supposed to measure goodness, though. That's what we have to keep in mind and where I agree with what MyUniBroDavis was probably referring to. When we evaluate a player, we take his role into account. Whenever a player is being used the wrong way, we use this in our evaluation. Whenever a player with obvious deficiencies has a perfectly suited role that cannot or can only hardly be replicated, we use this in our evaluation. Whenever a player has a flawed approach to play the game in our opinion, but the team happens to rely heavily on what he does, we use this in our evaluation. You're going to see impact data that, even if we assume there's no noise and collinearity in it, doesn't necessarily capture exactly what you're looking for or trying to evaluate.

Re: Ellis and Davis. First of all, let me say that RAPM isn't gospel and we shouldn't treat it as such. Aside from what I wrote above, collinearity certainly is an issue and the sample size, although big enough to provide at least somewhat resilient information, still isn't ideal. Anyway, when we look at Ellis we see that he has a reduced role on offense this season. His USG% is at the lowest point since his rookie season. This means inefficient offense might very well be still existent but it doesn't carry as much weight since his inefficient approach is less emphasized when he's on the court. Davis, on the other hand, has a clearly higher USG% and his team's offense is built around him to a higher degree. When such a player, as it is the case with Davis, struggles to deal with his role on offense then his influence - negative or positive - is going to be more emphasized by impact stats regardless of whether he's a superior offensive player or not. On defense it's also not hard to see why Davis impact is only slightly positive according to DRAPM. Raw on/off-numbers suggest basically neutral impact on that end and while this is of course clearly insufficient to reach a resilient conclusion because it lacks any context we have to take into consideration and because it is completely unadjusted, hence sharing the time with certain players more or less is going to heavily influence your individual on/off numbers, it gives us a first idea of what to expect. Then we have scouting which tells us that his defense still has a long way to go to get where it could be and we can also see that the Pelicans with Davis on the court have a pretty bad DRTG that cannot fully be explained by Davis being surrounded by defenders so poor that his individually very impactful defense is being offset. Ellis DRAPM is hard to believe, yes, but we can try to explain it and put it in context. Keep in mind that RAPM only knows thousands of data points and nothing about reputation, scouting etc. pp. What we see first is that the raw on/off-numbers show no defensive improvement when Ellis is on the bench. WOWY data shows us that Ellis spends most of his time with Paul George on the court who is considered to be a good defender. It's entirely possible and plausible that Ellis - maybe not being as bad as his reputation would suggest this season - has a relatively high DRAPM because the lineup-data we have isn't able to share the correctly (yet), assuming Ellis in fact doesn't deserve as much credit as he gets for the defense of the line-ups he's in.

We know this possibility, and we also have other tools in our evaluation-box, so that we don't have to look only at RAPM and shouldn't do it either. At the same time, we shouldn't disregard the tool RAPM is just because we don't agree with particular numbers because it definitely has its value. Like always, we must look at everything valuable in order to evaluate a player as good as possible with the limited information we have. Then, after taking everything into consideration and explaining discrepancies with rational reasoning, we might be able to get a pretty accurate idea of what a player contributes to his team. A different approach, like trusting a single stat - probably because it ranks the players closest to one's own personal and prejudiced opinion - is doomed to fail if it's supposed to evaluate a player as a whole (and create a ranking).

[lorak]

I dont trust any stats that put Monta Ellis over Anthony Davis.

Monta 0.0 RPM
Davis +2.7 RPM

was referring to multi-year RAPM

Which one exactly?

[cpower]

On a pure impact basis it's understandable why Davis ranks so low.

His offense is not being used right

And his defense, which started out well, has progressively gotten worse as the season goes on.

well, still way better than someone doesn't know how to play offense and defense at all.

RAPM isn't supposed to measure goodness, though. That's what we have to keep in mind and where I agree with what MyUniBroDavis was probably referring to. When we evaluate a player, we take his role into account. Whenever a player is being used the wrong way, we use this in our evaluation. Whenever a player with obvious deficiencies has a perfectly suited role that cannot or can only hardly be replicated, we use this in our evaluation. Whenever a player has a flawed approach to play the game in our opinion, but the team happens to rely heavily on what he does, we use this in our evaluation. You're going to see impact data that, even if we assume there's no noise and collinearity in it, doesn't necessarily capture exactly what you're looking for or trying to evaluate.

Re: Ellis and Davis. First of all, let me say that RAPM isn't gospel and we shouldn't treat it as such. Aside from what I wrote above, collinearity certainly is an issue and the sample size, although big enough to provide at least somewhat resilient information, still isn't ideal. Anyway, when we look at Ellis we see that he has a reduced role on offense this season. His USG% is at the lowest point since his rookie season. This means inefficient offense might very well be still existent but it doesn't carry as much weight since his inefficient approach is less emphasized when he's on the court. Davis, on the other hand, has a clearly higher USG% and his team's offense is built around him to a higher degree. When such a player, as it is the case with Davis, struggles to deal with his role on offense then his influence - negative or positive - is going to be more emphasized by impact stats regardless of whether he's a superior offensive player or not. On defense it's also not hard to see why Davis impact is only slightly positive according to DRAPM. Raw on/off-numbers suggest basically neutral impact on that end and while this is of course clearly insufficient to reach a resilient conclusion because it lacks any context we have to take into consideration and because it is completely unadjusted, hence sharing the time with certain players more or less is going to heavily influence your individual on/off numbers, it gives us a first idea of what to expect. Then we have scouting which tells us that his defense still has a long way to go to get where it could be and we can also see that the Pelicans with Davis on the court have a pretty bad DRTG that cannot fully be explained by Davis being surrounded by defenders so poor that his individually very impactful defense is being offset. Ellis DRAPM is hard to believe, yes, but we can try to explain it and put it in context. Keep in mind that RAPM only knows thousands of data points and nothing about reputation, scouting etc. pp. What we see first is that the raw on/off-numbers show no defensive improvement when Ellis is on the bench. WOWY data shows us that Ellis spends most of his time with Paul George on the court who is considered to be a good defender. It's entirely possible and plausible that Ellis - maybe not being as bad as his reputation would suggest this season - has a relatively high DRAPM because the lineup-data we have isn't able to share the correctly (yet), assuming Ellis in fact doesn't deserve as much credit as he gets for the defense of the line-ups he's in.

We know this possibility, and we also have other tools in our evaluation-box, so that we don't have to look only at RAPM and shouldn't do it either. At the same time, we shouldn't disregard the tool RAPM is just because we don't agree with particular numbers because it definitely has its value. Like always, we must look at everything valuable in order to evaluate a player as good as possible with the limited information we have. Then, after taking everything into consideration and explaining discrepancies with rational reasoning, we might be able to get a pretty accurate idea of what a player contributes to his team. A different approach, like trusting a single stat - probably because it ranks the players closest to one's own personal and prejudiced opinion - is doomed to fail if it's supposed to evaluate a player as a whole (and create a ranking).

if you don't agree on this particular numbers, would you trust other numbers? It is very hard to tell which number has noise and which ones do not. From a non-basketball fan's perspective , player A has more impact than player B. It just happens to be player A is Monta Ellis and player B is Davis.

[cpower]

Monta 0.0 RPM
Davis +2.7 RPM

was referring to multi-year RAPM

Which one exactly?

https://docs.google.com/spreadsheets/d/12rcLDCaJSh_b1hA3UyLG5-neayTBl_weqNVCGM0LheA/edit

[Woodsanity]

Really nice to see DJ develop into the best defensive player in the game

I'll admit that this test case really turned me off of RPM entirely.

He isn't the best defender but he is up there. The Clips have pukeworthy wing defenders.