Doctor MJ wrote:sp6r=underrated wrote:I have another philosophical point for people who have a strong belief in the value of RAPM. RAPM is considered part of the plus/minus family. Plus/minus stats are really individual point differentials. RAPM, APM and other similar stats are attempt to adjust for external factors and arrive at true individual point differential.
If you really have a strong belief in the value of RAPM and APM I don't know how you cannot heavily rank teams by point differential. Say what you will about a stat such as SRS there is far less adjustments involved in calculating a team's true point differential than there is for an individual's true point differential.
In short, I think if you have a strong believe in individual point differential it is only logical to have an extremely strong belief in the validity of team point differential as the basis for ranking teams. This calls for heavy revisionism as much as RAPM.
I don't know if I really see this as something that will cause heavy revisionism for many people. I'd imagine most people using advanced +/- stats are already pretty well versed in SRS. You're right though it wouldn't make sense to believe in +/- stats and scoff at SRS though.
When I said this calls for revisionism I am primarily referring to posters on this message board rather than the statisticians who make these stats. The later do understand the importance of point differential but IMO many posters who strongly advocate for RAPM downplay team point differential.
Consider the following clubs
1985 Lakers
1987 Lakers
1989 Pistons
1990 Pistons
1994 Rockets
1995 Rockets
2005 Spurs
2007 Spurs
2008 Celtics
2012 Heat
2013 Heat
The Bad Boys Pistons and mid 00s Spurs are routinely disparaged as opportunistic champions who never really reached greatness. By contrast the Showtime lakers, recent Heat and even to a lesser degree 95 Rockets are regarded as truly great teams:
Here are there RS SRS and RS+PS SRS
1985 LAL: 6.48, 7.64
1987 LAL: 8.32, 9.07
1989 DET: 6.24, 7.08
1990 DET: 5.41, 6.18
1994 HOU: 4.19, 4.91
1995 HOU: 2.32, 3.61
2005 SAS: 7.84, 7.86
2007 SAS: 8.35, 8.22
2008 BOS: 9.31, 8.87
2012 MIA: 5.72, 6.82
2013 MIA: 7.03, 7.35
Ranked by RS SRS
2008 BOS: 9.31
2007 SAS: 8.35
1987 LAL: 8.32
2005 SAS: 7.84
2013 MIA: 7.03
1985 LAL: 6.48
1989 DET: 6.24
2012 MIA: 5.72
1990 DET: 5.41
1994 HOU: 4.19
1995 HOU: 2.32
Ranked by RS+PS
1987 LAL: 9.07
2008 BOS: 8.87
2007 SAS: 8.22
2005 SAS: 7.86
1985 LAL: 7.64
2013 MIA: 7.35
1989 DET: 7.08
2012 MIA: 6.82
1990 DET: 6.18
1994 HOU: 4.91
1995 HOU: 3.61
Let’s look at this list carefully.
How can the mid 90s Rockets not be regarded as maybe the worse NBA champion post 1980 if you have a strong belief in point differential?
They’re a total outlier from a point differential perspective. In comparison to these clubs. Only the 88 lakers and 06 Heat have similar SRS.
How can the best single season Showtime lakers clubs be regarded as a massive step up from the best mid 00s Spurs from a point differential perspective?
They are right next to each other.
How can the Heat be considered near GOAT squad from a point differential perspective?
The current Heat do not come close to the top of the list and are far closer to teams such as the Bad Boy Pistons than Jordan’s Bulls.
It is really hard for me to understand how RAPM could hold such influence on people while also believing things such as Showtime Lakers >>> mid 00s Spurs, 95 Rockets great teams, Heat near-GOAT level and other things I haven't touched here. Yet I routinely read posts were that is the case. So no I don’t think team point differential has had nearly the impact on team evaluations that RAPM has on individual evaluations. Well at least in this community.
That is shocking because it is easier to evaluate a team statistically than it is to evaluate an individual statistically. If people really are heavily influenced in RAPM to such a degree that it can cause them to revisit debates that were settled in their mind such as Stockton-Malone** they should be even more influenced by statistical analysis of team point differential.
So far that hasn't really occurred.
.Note: my post-season SRS is a back of the envelope calculation that weighs HCA at 3 points. It doesn’t perfectly match b-r’s results but it is a fair approximation.
** When I say settled debates I am explicitly
NOT referring to TD-KG. The great posts by drza, one of the best posters on this board, along with others have really settled that TD only developed this clear margin in the public eye due to the disastrous management of Minnesota.
*** One last totally stray thought, when I say Minnesota had terrible management I am not including Flip. Flip is actually a pretty good coach and is unjustly maligned despite some clear flaws.