APBRmetrics

[Kevin Pelton]

I can't seem to find a link an hour or two later, but Protrade -- the pseudo-fantasy/stock market site that incorporates statistical analysis with those two things -- had an article from Ben Alamar analyzing the 2005 NBA Draft.

Ben's been good at chatting about his methods on the comment threads at FootballOutsiders.com, and I was wondering if one of our connected folks (Roland or DeanO) could invite him here; I'd love to discuss what seems like a unique methodology for analyzing the draft.

[moneyp]

http://www.protrade.com/insight/InsightArticleAlamarRevisitingTheNBADraft.html

Interesting site.

[gkrndija]

That was a really bad article. He completely ignored eFG% when analyzing players and he completely ignored pace. Arguably, the 2 biggest fundamentals of apbrmetrics.

What's worse is that he seems to have read about things like skill curves and still manages to miss the point. Scoring Efficiency does not drop according to minutes played according to the book.

He also completely dismisses Salim Stoudemire from any NBA success because of his poor asst/TO ratio(0.91). That seems a little short sighted considering Reggie Miller and Alan Houston also had less than stellar ratios coming out of college.

I didn't read past the Atlanta preview.

[benalamar]

Thought I'd justify my exclusion of Stoudimire a little bit.

The players mentioned about Houston and Miller, both had significantly better asst/to ratios (1.1 for Houston and 1.14 for Miller) than Stoudimire (0.91). In the 20 years of NBA draft data I have, no guard came out of college and had NBA success (by the measure used in the article) with that low a ratio. It just didn't happen.

If, however, he is included in the analysis, he would have ranked 43rd out of 43 players (due in large part to his low ratio).

[gkrndija]

[benalamar]

I don't think that the ranking is that off base. If you look at PER, Stoudimire ranked 39th among players that had declared for the draft and his PER dropped against top quartile competition. Now the model does have a bias against seniors so that may drag him down the rankings, but even without the bias, he does not look good.

I thought about relying just on one season of data for the model, and tried to go back and use multiple seasons, but found almost no correlation to previous seasons with future success, once the last year in college was included. Stoudimire could end up being a statistical oddity, and he does have a small probability of actually becoming successful, but the odds are against him.

[gkrndija]

PER is a cool stat, however it's not perfect. They're great at getting a general idea of who are the best players from the boxscores, but it is not the holy grail of rankings.

For Example Drew Gooden(25th) and Memo Okur(32nd) were ahead of players like Ben Wallace(41st) and Rasheed(66th) in PER last year. The Wallace brothers are better than Gooden and Okur, letalone that much worse.

PER also gives too much credit to things like defensive rebounds and assists. A team would rather take a player who averages 5 blks/gm rather than 6 assists/game. Yet the 2 players would have almost the same PER. It is also less reliable in the college game because of the varying schedules and opponents teams play.

Salim probably won't be an all-star and will face an uphill battle to make it in the league as a 2nd rounder playing on a team loaded with swingmen, but he's not the worst college player in the draft.

[jemagee]

[Kevin Pelton]

Can we save the PER discussion for elsewhere? The PER issues pointed out don't really explain why Stoudamire rates poorly.

I do tend to disagree with the Stoudamire discussion. Profit shot 31.2% on 3s as a senior. Dehere was much better (39.6%) but still nowhere near the 50+% Stoudamire shot. I'm more of A/TO fan than most here, but I think separating into Assist Rate and TO Rate captures the fact that Stoudamire just doesn't get a lot of assists.

I was a little surprised to see that subjective Stoudamire comp Steve Kerr had such an outstanding A/TO ratio as a senior (a little better than four to one), though he of course wasn't playing alongside Mustafa Shakur.

[kbche]

What is the origin of the assist/TO ratio significance? This ratio will approach infinity as TO approaches 0 regardless of the number of assists. Also, how does this ratio correlate with other commonly used stats? Assists are difficult to conceptually use in any predictive manner because they are highly dependent on other basketball stats.

KAB

[JonathanG]

Coming from a more traditional scouting point of view, I really have to question ranking NBA draft prospects solely based on their statistical production. Defensively is where this kills me the most. There is just no way you can rank a guy's defense based strictly off his steals, blocks and rebounds.

I didn't dig that deep into the numbers last year (certainly not the way that a lot of you guys do), but I would imagine that using that kind of criteria, a guy like Michael Harris from Rice would rank as a lottery pick in an article like that while Deron Williams would probably go in the 2nd round. Its never that simplistic. As Kevin implied by mentioning the potential factor, players don't get drafted based on the type of players they are right now, they are drafted based on the kind of pros teams project them to evolve into. There are many examples of players who had unimpressive stats in college from an efficiency standpoint or however you want to call it, but still went on to have fantastic NBA careers in the long run.

There also seem to be quite a bit of inaccuracies in this article. It says for example that Travis Diener "shot only 42% from the field, worst in the draft." Just off the top of my head, I can tell you that Linas Kleiza shot worse at around 40% from the field, so Diener definitely isn't the worst here. There are probably others. But let me ask you, does shooting 43% from behind the arc as a junior/senior on a high number of attempts as your team's first (only?) offensive option not count for anything anymore? Especially when the same guy got to the line almost 6 and a half times per game. I'm not much of a stats guy, but in my opinion that's pretty damn impressive. This has been harped on already, but the 7 assists to 2.5 turnovers per game on a mediocre team with very little offensive firepower besides him is something that HAS to be taken into consideration here. Especially when Salim Stoudamire gets completely written off because of that same stat. I thought that Diener would be a guy that would be severely overrated by an article like this, but for some reason he gets killed.

Another example...the writer calls Julius Hodge a better shooter than Rashad McCants. Has he ever bothered watching either of these guys play? Then he goes on to write that Bracey Wright (41% FG, 33% 3P) "shoots well from the field".

All in all I think this guy really plays around with the numbers and just draws whatever is convenient for him, which is probably the #1 thing that frustrates me the most with certain people using stats to make a point.


Lemme stress that I think there is certainly value in analyzing NCAA statistics to a certain extent, but not in such a conclusive way that puts this kind of stuff in such a black and white context. For the most part we are talking about players who have not yet come into their own as basketball players. There is a way to use this data in a way that makes sense, but only as just another tool that can be used to evaluate pro potential, definitely not the only one.

[John Hollinger]

Actually, the A/TO difference between Kerr and Stoudamire is pretty easy to figure out -- Kerr played the point, and Salim didn't.

[benalamar]

To start, I'd like to agree with Johnathan, that you cannot do drafting based on stats alone. I would never seriously suggest otherwise. Statistical analysis has alot to offer, but it is part of the story, not the whole book.

As for questions on the model:

>Given how important measuring potential is in comparing guys who >come out after their freshman and senior seasons, I'd like to hear more >about how potential was accounted for.

I simply used draft age and found that this a negative impact on the projected probability of success that differed by position.


>Am I safe in assuming these are Dean's Offensive/Defensive ratings? Is >this over the course of their careers?

Yes these were Dean's numbers, but I only used the level at year 3. Originally the analysis was planned to check success at years 1, 3 and 5 seperately and examine the differences, but some plans are grander than alotted the alotted time.

>I'm curious what statistics you used or started with. Were you looking >more to measure performance or skills?

I used a lot of different statistics including stadard per game and per minute variables, PER (not to get the PER discussion started again), physical variables such as height and weight, total games played etc. This was largely a kitchen sink type of project where I looked for the statistically significant varaibles.

[Kevin Pelton]

Ben, I forgot in my first post to thank you for dropping by. Much appreciated.

[Mark]

Salim Stoudamire's first season: 12.5 PER, but .545 TS%. Both sides of the earlier discussion can probably say they were partially right.

What did the first year performances suggest to folks about projection methodology and improvements?

What is to come from this crop in NBA? Any picks for surprise changes from 1st year results?

I'll venture that Danny Granger continues up and gets more press. His 3pt%/inside shot% combo rating was 33%/33%. If he moved closer to 40/40 that would be great for him and the team.

And for the next draft crop? Now that teams are known, any further more specific predictions?

Larry Bird also got Shawne Williams and James White, 2 other players who should go at least 30/30 and hopefully for them closer to 40/40. Toronto might want Bargnani eventually to be 40/40 along with Charlie V. but I assume his inside shot % will probably start in the 20s.
Foye and Douby probably rate somewhere in 30s/30s and perhaps others will too- but not sure what to expect from Roy, Gay, Brewer on 3pt%. How much will Morrison go inside?

I also noticed this piece today on Jordan/Morrsion pick. I heard Jordan had to warm up to the idea and the majority of the other voices were enthusiastic for Morrison earlier before he came around to agreeing.
http://www.protrade.com/insight/InsightArticleDetail.html?sp=KRC4706009&x=x
I assume using a value added perspective Morrison's expected scoring trumped Thomas or Gay in other areas.

this link can be used to get back to the original 2005 draft article
http://tinyurl.com/l33jr

Generally pretty good set of projections, looking back at them. One on the other side, I expected Frye to do quite well (just on gut feel, not detailed study) but the article's assessment was more cautious.