BPM and VORP

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Crow
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Re: BPM and VORP

Post by Crow » Wed Apr 18, 2018 6:05 pm

Basketball-Reference has BPM / VORP and it says:

Stockton almost 3 times Nash's BPM for career regular season. Twice the career VORP. Higher BPM than Nash's best season 9 times. 60% better career playoff BPM. Neither a good defender in regular season but Nash 3 times as bad. Stockton a modest positive defender in playoffs, Nash a much more modest negative than in regular season. Nash almost matched Stockton for peak year OBPM. Stockton with a small lead on career RS OBPM and a bigger lead on career playoff OBPM.

You'd have to try to find a different metric or a variable assist credit where Nash shone far more brightly for Nash to win the comparison. WS/48 favors Stockton career regular season & playoffs. Stockton beats Nash's peak rs year 4 times here. Beats peak playoff performance too.

eminence
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Re: BPM and VORP

Post by eminence » Wed Apr 18, 2018 8:10 pm

bchaikin wrote:Stockton's assists were not as high value--in other words, his passes did not create the high value shots to the same level Nash did. Nash's skill created very high value shots for the players he passed to.

a nonsensical statement unsupported by facts...

over the 7 year stretches mentioned above both players threw for 1000+ more assists than any other player in the league during those times, and both PGs' teams lead the league in eFG% over those long 7 year periods...

yet somehow one player's assists were of higher value than the other's?...

you also sidestepped the question of what was the offensive BPM/VORP of nash versus stockton...

i'm also curious as to the defensive BPM/VORP of both players, and the overall ratings - who does BPM/VORP say was the better player?...
Forget the numbers, re-watch some games of each, and I expect that you'll come to the same conclusion that Nash puts more pressure on a defense than Stockton did.

Crow
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Re: BPM and VORP

Post by Crow » Thu Apr 19, 2018 12:36 am

I'm almost never going to forget the numbers.

In this case, I'll suggest adding more. With video based tracking data, should be able to count double teams drawn (on drives and other plays), as well as number of defenders who don't come all the way over but respond by putting one or both feet in the paint on the play. "Space" value is being calculated. "Pressure" should be too, beyond scoring at rim and ftas by the driver or a dish recipient. Eyes might be right; but if you can verify and learn more about the trends. How do variations of pressure vary on impact? Penetration within x feet of rim vertically and y feet of rim on the horizontal? Degree of separation (from original defender and anyone), speed / ETA to rim? Options? Estimated expected points of best option (calculated once at certain distance or every tenth of a second)?

Mike G
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Re: BPM and VORP

Post by Mike G » Thu Apr 19, 2018 12:59 am

Every assist led to a 100% made shot.

Crow
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Re: BPM and VORP

Post by Crow » Thu Apr 19, 2018 1:33 am

You can stop there, or forget the numbers... or go on.

eminence
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Re: BPM and VORP

Post by eminence » Thu Apr 19, 2018 4:32 am

Think of 'forget the numbers' more as 'blank the mental slate' I suppose. I forget I'm chatting with a bunch of statisticians at times :)

Crow
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Re: BPM and VORP

Post by Crow » Thu Apr 19, 2018 9:24 am

Or open another or a few more windows. At least one for new stats and one for thinking beyond stats, at least for a moment.

Mike G
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Re: BPM and VORP

Post by Mike G » Fri Apr 20, 2018 12:24 am

eminence wrote: Forget the numbers, re-watch some games of each, and I expect that you'll come to the same conclusion that Nash puts more pressure on a defense than Stockton did.
Is it possible Nash had better shooters around him than Stockton did?
If so, it might mean 10 good passes from Stockton result in 5 assists, while from Nash it would be 6.

It just seems a funny spin on things to say Nash passes led to high% shots, compared to Stockton's. The same logic says that Stockton on the mid-00's Suns would have gotten a lot more assists than he got in Utah.

Stock also had 3x the steal rate.
http://bkref.com/tiny/niCdA
Career Ast%: Stock 50.2 - 41.5 Nash

eminence
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Re: BPM and VORP

Post by eminence » Fri Apr 20, 2018 3:30 am

Mike G wrote:
eminence wrote: Forget the numbers, re-watch some games of each, and I expect that you'll come to the same conclusion that Nash puts more pressure on a defense than Stockton did.
Is it possible Nash had better shooters around him than Stockton did?
If so, it might mean 10 good passes from Stockton result in 5 assists, while from Nash it would be 6.

It just seems a funny spin on things to say Nash passes led to high% shots, compared to Stockton's. The same logic says that Stockton on the mid-00's Suns would have gotten a lot more assists than he got in Utah.

Stock also had 3x the steal rate.
http://bkref.com/tiny/niCdA
Career Ast%: Stock 50.2 - 41.5 Nash
The Suns absolutely had better shooters, simply the way league trends were going (spearheaded by those Suns). Not sure how it'd balance out with the shift to the 3pt line hurting modern playmakers in terms of generating assists.

Mike G
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Re: BPM and VORP

Post by Mike G » Fri Apr 20, 2018 9:26 am

I'm surprised to hear the trend toward more 3FG would hurt assist totals, since a high % of 3's are assisted.
Do you mean that it's now less the exclusive job of the primary distributor, and assists are spread around more among teammates?

Assists were most abundant in the mid-80's, but pace was higher, too.
Averaging 3-year blocks, starting with 1974-76, it looks like this:

Code: Select all

As/FG  3PAr  Ast/G  Season   Pace  A/100
.563   .000   23.8   1976   105.9   22.5
.571   .000   24.9   1979   106.3   23.4
.589   .027   25.5   1982   101.9   25.0
.599   .029   26.1   1985   102.2   25.6

.608   .049   25.9   1988   100.8   25.7
.600   .077   25.1   1991    98.9   25.3
.607   .103   24.5   1994    96.2   25.5
.613   .200   22.7   1997    91.6   24.8
.608   .165   21.7   2000    90.8   23.9
.606   .178   21.7   2003    91.0   23.9

.592   .195   21.1   2006    90.5   23.3
.578   .219   21.4   2009    92.0   23.2
.572   .223   21.2   2012    92.0   23.1

.589   .257   22.0   2015    93.3   23.6
.583   .313   22.7   2018    96.5   23.5
I've broken it into pre-Stockton, the Stockton era, the Nash era, and post-Nash.
3PAr = 3fga/fga. A/100 = Ast/100 possessions.
The Nash years really were lowest since the mid '70s in Ast/100 poss.
What accounts for diminishing Ast/FG ratio as 3PAr rises? Teams don't seem to be jacking up their home assist totals as much lately.

EDIT -- Indeed, the disparity between home and away Ast/FG is a fraction of what it was 18 years ago:

Code: Select all

As/FG  home   away    H/A
2000   .625   .587   1.064
2005   .608   .576   1.056
2010   .578   .548   1.055
2015   .596   .578   1.031
2018   .592   .579   1.023
2010 was anomalous, nearly an all-time low in reported Ast/FG ratio.
The home/away ratio (of these ratios) has steadily dropped since 2000 at least. That final column is what home scorekeepers have jacked up their own players' assist totals, relative to what the rest of the league grants. It varies from team to team, of course.
Before 2000, you have to look up individual teams' splits. You have to anyway, to adjust player assists to the unjacked "real" amounts.

I'm pretty sure there were years when the whole league approached 1.10 "jack factor"; and some teams have been > 1.20
Stockton's Jazz tended to be about half as bad as most. He deserved all his assist titles. Magic enjoyed high home bias.
Chris Paul got one that Nash should have had, if I recall correctly.

bchaikin
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Re: BPM and VORP

Post by bchaikin » Sat Apr 21, 2018 12:20 am

Stockton almost 3 times Nash's BPM for career regular season. Twice the career VORP. Higher BPM than Nash's best season 9 times. 60% better career playoff BPM. Neither a good defender in regular season

if this is indeed what BPM/VORP says, that stockton was not a good defender in the regular season, then what does that say about them as valid defensive metrics, considering:

(a) stockton was named all-D 2nd team 5 times over a stretch of 9 seasons (8889-9697). the only PGs named ahead of him these 7 seasons as all-D 1st team were gary payton (4 times) and mookie blaylock (2 times). so in the eyes of the all-D voters, stockon was clearly one of the top defensive PGs in the league, for a long time...

(b) over the decade of 8788-9697 utah was the 2nd best defensive team in the league at just 103.4 pts/100poss allowed (only new york was better), and stockton played 1/6 to 1/7 of the team's total minutes played (karl malone 1/6, mark eaton 1/14 to 1/15)...

i'd say they don't measure defense very well...

Forget the numbers, re-watch some games of each, and I expect that you'll come to the same conclusion that Nash puts more pressure on a defense than Stockton did.

you can expect it all you want, but you'd be wrong...

from 8990-9798, a 9 year stretch (not just 1 season mind you but a full 9 seasons) stockton shot 55% on 2s, 40% on 3s, 82% on FTs, an overall high 60.4% ScFG% (17.2 pts/40min), all while attempting the 3rd most FTs among all PGs and passing for 2700 more assists than anyone (that's 300 more assists on average than anyone each season)...

over the past 4 decades i'd say no PG put more pressure on opposing teams than did stockton for as long as stockton did, other than perhaps PGs like magic johnson and chris paul (and eventually stephen curry)...

Mike G
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Re: BPM and VORP

Post by Mike G » Sat Apr 21, 2018 1:40 am

bchaikin wrote:... over the past 4 decades i'd say no PG put more pressure on opposing teams than did stockton for as long as stockton did, other than perhaps PGs like magic johnson and chris paul (and eventually stephen curry)...
Most Offensive Win Shares since 1978 by G or G-F:

Code: Select all

guard      OWS
Jordan    149.9
Stockton  142.8
Reggie    140.4
Paul      122.3
Kobe      122.1
Nash      113.7
Allen     111.7
Magic     110.6
Payton     96.7
Billups    92.4
Drexler    85.6
Harden     80.5
Carter     80.0
Hornacek   76.6
Wade       73.2
Porter     71.9
http://bkref.com/tiny/hvLha
This is every G and G-F with half as many OWS as Stockton in RS.
Curry now ranks #20, after KJ, Terry, and Andre Miller.

jgoldstein34
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Re: BPM and VORP

Post by jgoldstein34 » Fri Apr 27, 2018 2:42 pm

Nash was a higher leverage and better passer than Stockton. Assist numbers are actually a horrible measure of creation. Stockton is an all-time PG, but Nash is one of the most underrated offensive players ever.

I also love the irony of someone saying watch the games to see what I mean and all the replies being a list of stats.

Crow
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Re: BPM and VORP

Post by Crow » Fri Apr 27, 2018 4:05 pm

BPM / VORP are somewhat unsatisfactory measures of player defense given the way shot defense is dealt with and given that it is about 40-50% of total defense. But it is one of the measures we have for back then. I need to dig up the implied RAPM stuff. Anybody got the link handy?

Of course some of us did watch hundreds or thousands of NBA games before 2000
or 2010. (put me in the thousands group; add listening before or after cable TV and it is many hundreds more) with plenty- likely well over a hundred each- of Stockton and Nash games. I am pretty sure that applies to some others in this thread. And some may have watched a quantity since to catch up. (There are surely some / many who watch more than I do now. Different histories. Celtics playoff games in 60s? Saw some... on the one small black n white tv... when no one else was viewing and I could sneak it in.)

There are those willing to make judgments from tape and others ( including me) who might defer giving judgments from them for various reasons or insufficient interest in the debate, so far. If I can't PROVE my eye evaluation or memory of it is right or more right than yours, I may not try doing THAT.

Does PIPM go back far enough to make a Stockton - Nash comparison?

Mike G
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Re: BPM and VORP

Post by Mike G » Fri Apr 27, 2018 5:52 pm

It would be nice to see a study of how different shooters had better rates with Nash vs without; likewise with Stockton.
Some of us really don't have the time or inclination to watch dozens or hundreds of games; and then still not know if they were representative. And even then, you've just got a subjective conclusion, or none.

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