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Marty Burns SI.Com Article on Innacurate Stats
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phxgummer



Joined: 20 Jun 2005
Posts: 1
Location: Phoenix

PostPosted: Wed Apr 25, 2007 8:05 pm    Post subject: Marty Burns SI.Com Article on Innacurate Stats Reply with quote

I did not see any comments on Marty Burns article on the inaccuracies of NBA stats this season- lowest average of blocked shots and steals to lead the league. He attributes it to the fact that the league has moved statisticians off the scorers table to seats that are far from the floor, obstructed views and more.

Talking to a friend of mine who does statistics for one of the teams, I find that this is just the tip of the iceberg. The stats for many teams are totally innacurate and the league does not care. He told me to tape a game on TV (told me which teams had historically bad stats) and download a play by play from NBA.Com and compare what I see. He was right. Probably 10-15 discrepancies from what I saw and what was recorded and I don't know the scoring rules (but I do know the players and I can identify a rebound and a block).

How can the NBA allow this? How can people who care about stats allow this to go on- it is the history of the game! I will no longer participate in basketball fantasy now that I know that the numbers are not legit.
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deepak_e



Joined: 26 Apr 2006
Posts: 319

PostPosted: Wed Apr 25, 2007 8:24 pm    Post subject: Reply with quote

I guess the key question is here if these inaccuracies tend to even out over the course of a season, or they consistently overcount or undercount certain stats.

It could be an interesting study to sample 5-10 games from every NBA team, audit the boxscores, and see if some teams tend to be worse than others for various stats.
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Mark



Joined: 20 Aug 2005
Posts: 807

PostPosted: Wed Apr 25, 2007 8:24 pm    Post subject: Reply with quote

I hadnt seen it. Thanks for the note. Here is the link:
http://sportsillustrated.cnn.com/2007/writers/marty_burns/04/06/blocks.steals.notes/index.html

Seat revenue prompted the change but if stats and particularly fantasy stats are part of the sales campaign maybe steps could be taken to address concern. I assume NBA team's own stat analysis relies on same source so maybe accuracy would be deemed important from that perspective.


Last edited by Mark on Wed Apr 25, 2007 10:54 pm; edited 1 time in total
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coach_dbop



Joined: 30 Mar 2007
Posts: 33
Location: California

PostPosted: Wed Apr 25, 2007 9:25 pm    Post subject: Reply with quote

I couldn't agree more with inaccurate statistics. If you go to most of the websites that are honored here and compare you will find many differences. I did however finally solve the problem with the players minutes played during the season. It appears for the past couple of seasons the NBA has gone to a new way of tracking a players minutes played in a game. In the past if a player played even less than a second he was credited for 1 minute played. Now if a player was to play 0.08 tenths of the final quarter he is credited for a game played but his minutes played with remain 0. In their player game logs if a player played 41:34 it will be rounded to the nearest whole number such as 42 and put under that players minutes for that game on his personal game log.

So for instance if you look at Chauncey Billups stats in the first 2 games against Orlando you will see on Billups game log that he played 41 minutes in game 1 and 42 minutes in game 2. On the Pistons playoff statistics Billups is credited for playing 82 minutes. Obviously 41+42=83 so I was able to finally find out how the NBA goes about doing this.

In game 1 according to NBA.com he played 40:32 which is rounded up to 41 minutes.

In game 2 according to NBA.com he played 41:32 which is rounded up to 42 minutes.

NBA.com i assume to get 82 minutes added 40:32+41:32 which equals 81:64. If you round that to the nearest whole number you get 82.

So while you will look at his game logs and see 42 and 41 the total number of minutes played will be determined on adding the boxscore minutes played and rounded.

This has been the case in the NBA for the past 2 seasons now, but if many teams and players for that matter stats are inaccurate I am very upset because I pride myself on giving people the accurate information that they are asking for.
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admin
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Joined: 30 Dec 2004
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PostPosted: Wed Apr 25, 2007 10:28 pm    Post subject: Reply with quote

Is this really that big of a deal? Marcus Camby had a late surge, and his average of 3.30 bpg ended up better than his 3.29 bpg mark from a year ago and Theo Ratliff's 3.23 in 2002-03. Only once in the last five years has the league's leading shot-blocker averaged more than 3.32 bpg.

As for the steals, steals per 100 possessions are also at an all-time low. I don't see how a reasonable argument can be made that statisticians are missing when the ball is stolen. How else would the ball get from one team to the other? Plus, the per-100 possession rate is essentially the same as last year (0.79 vs. 0.80).

Here's how the top five in steals per game compare the last two seasons:

Code:
2006-07         SPG   2005-06         SPG
-------------------   -------------------
Baron Davis     2.1   Gerald Wallace  2.5
Ron Artest      2.1   Brevin Knight   2.3
Caron Butler    2.1   Chris Paul      2.2
Andre Iguodala  2.0   Gilbert Arenas  2.0
Gerald Wallace  2.0   Shawn Marion    2.0


Nobody had a season as good as Wallace this year (himself included). You could argue that's because spotters are giving steals to the wrong player some percentage of the time, which would tend to hurt the top players. Or you could think it's just a fluke. I tend toward the latter.

Quote:
I will no longer participate in basketball fantasy now that I know that the numbers are not legit.

If you're arguing scorers are awarding things to the wrong players because they can't see, I suppose they would not be legit. But if you're arguing that they're not meeting some objective measure of a "block," "steal," "rebound," "assist," etc., I don't buy that.

There is on some level a platonic concept of each stat. However, no matter how much you try to keep it from being so, people are not always going to agree what is a block or not. There's not one objective standard.
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Dan Rosenbaum



Joined: 03 Jan 2005
Posts: 497
Location: Greensboro, North Carolina

PostPosted: Wed Apr 25, 2007 10:41 pm    Post subject: Reply with quote

Folks complaining about NBA statistics should really spend some time as a labor economist working with self-reported income data. NBA data is a dream relative to what I am used to working with in my day job. And that work that I do in my day job has at times helped drive important policy debates - stuff that is way more important than anything that NBA statistics are used for.

As I tell my students, working with data is like trying to put out a forest fire. When you first approach the forest fire, you concentrate your efforts in the areas that will save the most lives and property. But you allow lots of blazes to keep burning. So yes, it would be better if NBA data was recorded perfectly, but this strikes me as a second or third order problem - akin to the blazes that are not put out until very, very late in the process of putting out a forest fire.
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HoopStudies



Joined: 30 Dec 2004
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Location: Near Philadelphia, PA

PostPosted: Thu Apr 26, 2007 8:27 am    Post subject: Reply with quote

There are a lot of ways I think the stat taking can be improved in the NBA, but it is, as Dan says, not a big deal in the big picture. We can still do a huge amount with the numbers as they stand. Errors as they may affect fantasy hoops are probably not as big a deal in real basketball (I haven't played fantasy hoops, but it seems like individual stats matter a lot more there for winning than in real basketball).
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jeffpotts77



Joined: 18 Feb 2005
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PostPosted: Thu Apr 26, 2007 8:55 am    Post subject: Reply with quote

Dan Rosenbaum wrote:
So yes, it would be better if NBA data was recorded perfectly, but this strikes me as a second or third order problem


Out of curiosity, what's your top priority of what to fix?
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HoopStudies



Joined: 30 Dec 2004
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PostPosted: Thu Apr 26, 2007 9:19 am    Post subject: Reply with quote

jeffpotts77 wrote:
Dan Rosenbaum wrote:
So yes, it would be better if NBA data was recorded perfectly, but this strikes me as a second or third order problem


Out of curiosity, what's your top priority of what to fix?


Let me talk to the league about these first before getting into them in any public forum. I don't think they'd mind, but I don't want to take a chance.
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mikez



Joined: 14 Mar 2005
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PostPosted: Thu Apr 26, 2007 11:04 am    Post subject: Reply with quote

All of this stuff is a problem. But there are workarounds (for example, one could, if it turns out to be a big issue, see which scorers give out fewer assists, and apply a corrective factor, etc.), and the league is aware of these issues.

What actions can/will be taken to improve official scorers' accuracy is still an open question (though some things are going on behind the scenes that, like Dean, I'm unwilling to discuss here) but my guess is that if/when anything does happen you will not hear about it publicly.

-MZ
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deepak_e



Joined: 26 Apr 2006
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PostPosted: Thu Apr 26, 2007 12:46 pm    Post subject: Reply with quote

mikez wrote:
What actions can/will be taken to improve official scorers' accuracy is still an open question (though some things are going on behind the scenes that, like Dean, I'm unwilling to discuss here) but my guess is that if/when anything does happen you will not hear about it publicly.

-MZ


Why all the secrecy regarding this issue from the league?
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HoopStudies



Joined: 30 Dec 2004
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PostPosted: Thu Apr 26, 2007 1:31 pm    Post subject: Reply with quote

deepak_e wrote:
mikez wrote:
What actions can/will be taken to improve official scorers' accuracy is still an open question (though some things are going on behind the scenes that, like Dean, I'm unwilling to discuss here) but my guess is that if/when anything does happen you will not hear about it publicly.

-MZ


Why all the secrecy regarding this issue from the league?


While there is a process of trying to improve things and discussion is going on internally, it's a lot easier to have smaller conversations among those who work with the data on a regular basis.

Feel free to voice your wish list.
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jeffpotts77



Joined: 18 Feb 2005
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PostPosted: Fri Apr 27, 2007 11:23 am    Post subject: Reply with quote

HoopStudies wrote:
Feel free to voice your wish list.


Not sure why my post was deleted earlier but regarding a wish list, I put forth: charges drawn, deflections, setting picks, and goaltending.
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John Hollinger



Joined: 14 Feb 2005
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PostPosted: Fri Apr 27, 2007 11:35 am    Post subject: Reply with quote

I'll second that -- the stats as they currently exist treat defense as something of an afterthought. There has to be a better way. Tracking simple stuff like charges and goaltends seems to be a step in that direction.

Love the forest fire analogy, will have to remember that one. Actually maybe Dan has hit on something -- we can have self-reported basketball stats! "Ron Artest claimed to have 38 points and 14 rebounds as the Sacramento Kings defeated the Orlando Magic on Tuesday ...."
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kjb



Joined: 03 Jan 2005
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PostPosted: Fri Apr 27, 2007 12:42 pm    Post subject: Reply with quote

I'd like to see better criteria and consistency for awarding assists. The current awarding is pretty haphazard. It would also be good to get more consistent guidelines on crediting steals.

Beyond that, one possible way to increase accuracy would be to generate the pbp live, but then have it checked on tape the next day. I catch errors that way, and it would be easy to fix them if I had access.
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