Adjusted Plus-Minus

[Wannabe MEP]

I get trashed for my obsession with obscure stats, and Adjusted Plus-Minus is my favorite. No one else seems to like it (or at least no one on this board uses it as much as I do). While I do think it is extremely under-appreciated, I ABSOLUTELY DO NOT believe that it is some kind of holy grail of stats that can tell us everything. I think it has to be carefully sifted through.

Why (I assume) people don't like Adjusted Plus-Minus:
1) It's new. It hasn't gained enough traction with longtime basketball fans, because data hasn't been available until very recently.
2) It's incredibly abstract.
3) It doesn't correlate with fantasy leagues at all.
4) It completely ignores traditional stats.
5) It has nothing to say after a single game. If people want to use stats to argue about why we lost to the Lakers last night, they have to go to the box score.
6) It doesn't give clear answers. There are always more layers, extrapolation, sifting to find meaning.

Why I like adj +/-:
Basketball is incredibly complex, and the fan experience is incredibly superficial. 90% of what fans know about basketball comes from highlight reels and box scores. Box scores teach us to value the most superficial aspects of basketball, stats that--without exception--can be amassed selfishly in ways that harm the team. The most obvious example of this is points--if a player scores a lot of points, he will be praised for the most glorified of box score stats, but he may in fact have hurt his team if he scored those points selfishly/inefficiently. But the same is true of every single box score stat (although obviously rarer with assists, fg%, and offensive rebounds, for example).

The most glaring problem with the box score is that it is an absolutely worthless gauge of defense. Measuring defensive value by steals, blocks, and rebounds is like measuring the beauty of a woman by leg length, freckle count, and breast size.

Adjusted +/- measures on-court subtleties like unselfishness, hustle, defensive focus, offensive spacing, chemistry, help defense, feel of the game, etc. No other stat comes close. Good basketball is built on these subtleties.

OK. So what?
I still believe in this team because I believe in the personnel. Yeah, we may be one or two players short from being a great team, but I think we can become a very good team given time to develop chemistry.

But I think we have to massively redistribute playing time. I believe that there has been enough time in this season to make some clear pronouncements about this team using adjusted +/-. The greatest weakness with adj +/- is that it needs lots of data to really be effective. It's still early in the season, but combining this year's data, last year's data, and old multi-season adjusted +/- gives us a lot to work with.

What we know for sure based on adjusted +/-:
1) We are still better with Steve Nash on the court. And it's not even close.
2) We are better playing four out. Sometimes even with seemingly awkward, nontraditional lineups (like Dudley playing the four).
3) We are better with four three point shooters on the court.
4) We are better with Channing Frye on the court. All six of this year's positive units have Frye. 7/10 top units last year in the playoffs had Frye (more than Nash, Stat, JRich, etc). 7/10 top units during the regular season last year had Frye (also more than Nash, Stat, JRich, etc).
5) We are better with Jared Dudley on the court. The top seven units from the regular season last year, the top nine units from the playoffs last year, and the top four units from this year all have Dudley.

What we can probably conclude based on adjusted +/-:
1) Amare Stoudemire is overrated. True, we didn't adequately replace him, but we are actually missing Lou more than Stat.
2) Vince Carter is massively underrated. He is one of the best players in the league, in part because he is one of only a few players who helps his team significantly on both offense and defense.
3) Josh Childress should play. He has the third highest adj +/- so far behind Nash and Carter.

[sunsbum]

I agree with the last part of your post. Carter plays above average defense, never watched him close enough before to notice. Also, suns fans (especially most of the clueless posters on this board) really have no idea what josh childress is capable of. With playing time he can be a tayshaun prince clone. Lets not forget how important that guy was on the pistons during their glory years.

Hopefully we get some guys out of here and let childress shine.

[now and 4 life]

2) Vince Carter is massively underrated. He is one of the best players in the league

Wait what
If this stats claims this I would seriously suggest not likeing it as much as you do.

[Wannabe MEP]

2) Vince Carter is massively underrated. He is one of the best players in the league

Wait what
If this stats claims this I would seriously suggest not likeing it as much as you do.

A 2007-2008 adj +/- analysis by 82games.com using five years worth of data had him as 28th best player in the NBA.
http://82games.com/ilardi2.htm

That analysis separated offensive and defensive adj. +/-. Defensive adj +/- strongly favored frontcourt players. Carter was the third best guard, behind only Ginobii and Iguodala.
http://82games.com/ilardi2d.htm#table

This year's two year adj +/- has him as 8th best player in the NBA.
http://basketballvalue.com/topplayers.p ... =2010-2011

He has a very good net defensive rating (2nd best on the team behind only Bass) and a very good net offensive rating (2nd best behind only Jameer Nelson)--he's the only Magic player to have both.

[now and 4 life]

Which proves my point that this stat isn't very useful.

[Wannabe MEP]

Which proves my point that this stat isn't very useful.

Oh, ****. You proved it. Yep, several years' worth of in-depth, corroborating stats conclusively trumped by...now and 4 life's unsupported opinion.

I give up. Case closed. Forget all that **** I just said. I've been proved wrong.

[now and 4 life]

So you think Vince Carter is the 8th best payer in the league?
Must really suck for the Magic to lose a player of this caliber

Vince Carter was the third best Guard in 07-08 behind Iguodala?

Forgive me for not trusting a stat that reaches conclusions like this.

[Wannabe MEP]

So you think Vince Carter is the 8th best payer in the league?
Must really suck for the Magic to lose a player of this caliber

I think he is a very good player. By one measure with limited data, he is 8th. Is that the absolute measure of a player? Of course not. He is very likely top 30, but might be top 20 or top 10. This measure suggests he's top 10, but that's extremely difficult to say conclusively because there are so many variables. The creators of the formula would certainly not say that it is conclusive just based on that.

The biggest weaknesses of adj +/- are:
1) error due to small sample size
2) influence of teammates--some players are more valuable in some settings than they are in others
3) comparison to backups

The Magic were absolutely dominating teams while Carter was playing, but they were struggling when he was on the bench this year. His net rating so far this year was very, very good: 21st in the league. Why? Carter was incredibly valuable to the Magic because they were desperate for creative ballhandlers. They didn't have enough other options, especially off the bench. They were most effective offensively with both Carter and Nelson on the court together (but Carter was much more effective on defense). They had no creative ability when those two were on the bench.

If Carter had gotten injured, the Magic would have seriously struggled. But through trades they lost one creative ballhandler and got back three, two of which are more natural point-guard style facilitators, while Carter is more of a pure shooting guard. Despite giving up an incredibly valuable player in their system, they filled a crucial need.

Vince Carter was the third best Guard in 07-08 behind Iguodala?

I was saying that he was the third best guard defensively behind Iguodala according to that analysis.

The point, again, is not the specific rating exactly. The point is that he is a very, very good defender, which no one ever talks about. He is highly underrated, particularly as a defender.

[Frank Lee]

is like measuring the beauty of a woman by leg length, freckle count, and breast size.

Actually, the correct order is leg length, breast size, then freckle count.... and its a tried and true formula.

Years of research, Soles years of research. Not willing to let my life's work be diminished with such a fragile comparison to a 'box score'