Number Crunching

[airowe]

http://www.scacchoops.com/tt_NewsBreaker_External.asp?NB=3261

[91_92_01_10_15]

http://www.scacchoops.com/tt_NewsBreaker_External.asp?NB=3261

Fantastic article. It's nice to see some objective responses to common criticisms of this team. What interests me the most, however, is the following, from the article:


As alluded above, Duke struggles more than usual to get to the free throw line, and so cannot benefit as much from their high percentages from the line. While in most years, Duke has multiple players drawing more than 5 fouls per 40 minutes, only Scheyer is above that mark, and no one else is very close.

Why should this team have trouble drawing fouls? I realize that we do not regularly feed the post, but that is not uncommon for Duke teams. We do regularly drive the lane, however, which should generate more opposition fouls than we are getting. Also, we have had a great deal of attempted putbacks of our many offensive rebounds, with relatively few fouls called.

I am not generally a conspiracy theorist, but I feel that I must finally pose the following question. Is there an anti-Duke officiating bias? The premise for such a theory, in my mind, would be that officials, having repeatedly heard about a perceived pro-Duke bias over the years, are now (at least subconsciously) trying to compensate. After all, when will a college basketball official receive more criticism when he blows a call than if said call favors Duke?

Consider the following stats:


year DukeFouls OpponentFouls Disparity ConferenceRecord
1980-81 543 597 -54 6-8
1981-82 569 532 37 4-10
1982-83 675 629 46 3-11
1983-84 663 788 -125 7-7
1984-85 567 687 -120 8-6
1985-86 767 861 -94 12-2
1986-87 667 682 -15 9-5
1987-88 706 726 -20 9-5
1988-89 750 820 -70 9-5
1989-90 734 926 -192 9-5
1990-91 716 869 -153 11-3
1991-92 611 833 -222 14-2
1992-93 526 679 -153 10-6
1993-94 536 676 -140 12-2
1994-95 555 553 2 2-14
1995-96 593 583 10 8-8
1996-97 626 679 -53 12-4
1997-98 669 774 -105 15-1
1998-99 712 895 -183 16-0
1999-00 555 690 -135 15-1
2000-01 660 844 -184 13-3
2001-02 655 752 -97 13-3
2002-03 697 740 -43 11-5
2003-04 697 769 -72 13-3
2004-05 610 696 -86 11-5
2005-06 621 757 -136 14-2
2006-07 577 654 -77 8-8
2007-08 654 761 -107 13-3
2008-09 671 776 -105 11-5
2009-10 505 546 -41 11-2


unc2009-10 408 527 -119 3-9
unc2008-09 608 785 -177 13-3

Sorry, I'm not very good at tables.

[riverside6]

One point to add to your table. Duke is +53 in foul differential in home games and -12 in road games.

[91_92_01_10_15]

Yes, I accidentally posted before I intended to. More to come in a moment...

[91_92_01_10_15]

Yes, I accidentally posted before I intended to. More to come in a moment...

I haven't done any statistical analysis on the numbers above, but it certainly appears that something changed after the national championship in 2001. I don't think that it's a coincidence that it was that year that Billy Packer and Gary Williams combined to create a national story about "Duke getting all the calls." More on that here:

http://www.dukebasketballreport.com/articles/?p=266

All that being said, I'm certainly open to the possibility that the bias is mine here. If so, set me straight.

[riverside6]

I think there is a strong correlation in fouls called for a team and talent.

That said the talent on Duke's 2001-2 team (http://scacchoops.com/PlayerDatabase.asp?team=du&season=2002) was very similar to 2000-2001 (http://scacchoops.com/PlayerDatabase.asp?team=du&season=2001).

[Chitowndevil]

I think there is a strong correlation in fouls called for a team and talent.



Well, just based on the numbers in that table (Duke teams from 1980-2008), the sample correlation between Duke's conference winning percentage and foul margin (opponent's fouls minus Duke fouls) is 0.66.

I would have agreed with you but that number is actually much bigger than I'd have guessed. It is hugely statistically significant (for those that care the t-statistic in a regression of winning pct on foul margin is 4.66).

[Warning: very geeky part ahead] Now, the econometrician in me feels compelled to mention the obvious endogeneity problem: if some Duke teams did get more favorable officiating than others for whatever reason, those teams would be more likely to win. So we don't know which way the causality runs. To try something different, we'd need an instrument; that is, something that's correlated with foul margin but doesn't directly affect win percentage. If I had the data at hand I might try percentage of points scored by the frontcourt. Though given a stat I saw a year or so ago to the effect that the last few NCAA champs got 60% or more of their scoring from their frontcourt, I'm not completely sure that qualifies.

[superdave]

Ha Ha! I dont think you have to get too nerdy to see that inferior talent fouls superior talent. I think it's a combination of quickness, confidence/experience and aggression.

Aggressive offensive players get fouled a lot (Redick, Hansborough) and even know how to draw calls when a defender makes a mistake (confidence/experience). Quicker players put defenders on their heels and make them reach (Jason Williams, Wall).

And more talented teams have better conference records, right? Well, except for UNC's 7 McD's and GT's lack of cohesion in spite of its NBA front line.

[superdave]

I think these stats on getting to the free throw line more often and defending better against 2 point shots (transition D?) show us two huge ways Duke can improve in the next few weeks.

Also, in light of of our increased offensive efficiency when the tempo increases, it would be nice to see Duke push the ball up court more. Singler seemed to push it off a defensive rebound earlier this season, but stopped. Nolan is the only player to consistently push it off a defenisve stop.

[CrazieDUMB]

Also, in light of of our increased offensive efficiency when the tempo increases, it would be nice to see Duke push the ball up court more. Singler seemed to push it off a defensive rebound earlier this season, but stopped. Nolan is the only player to consistently push it off a defenisve stop.

This is another problem of causality. Usually when we get a lot of fast breaks they lead to high percentage buckets, raising our efficiency. That doesn't necessarily mean that if we try to push it past what we normally get, fast-break-wise, we'll score more efficiently. Indeed, it's possibly that if we try to force more fast breaks our efficiency will go down.

The question is how can we convert rebounds into fast breaks? Sometimes it just depends on being in the right place at the right time, with rebounds that are long, low and fast. Any ideas on this?

[Neals384]

Ha Ha! I dont think you have to get too nerdy to see that inferior talent fouls superior talent. I think it's a combination of quickness, confidence/experience and aggression.

Aggressive offensive players get fouled a lot (Redick, Hansborough) and even know how to draw calls when a defender makes a mistake (confidence/experience). Quicker players put defenders on their heels and make them reach (Jason Williams, Wall).

And more talented teams have better conference records, right? Well, except for UNC's 7 McD's and GT's lack of cohesion in spite of its NBA front line.

The attached spreadsheet proves statistically that Duke gets more calls in years when they win more games...or is it the other way around?

Anyway, I took the data from the table and put it into a scatterplot. The statiscally generated trendline shows that there is a correlation between wins and fouls (here I've reversed the numbers so that a positive foul disparity means Duke got more calls than the opponents).

On years where the plot point falls to the right of the trendline, you might well think "Duke gets all the calls". And in years where the plot point falls to the right of the trendline, "the refs have it in for Duke".

Note that the years from the mid 80s, early 90s and 2007 fell well to the right of the line, while most of the years after 2001 fall to the left of the line.

[Jderf]

Also, in light of of our increased offensive efficiency when the tempo increases, it would be nice to see Duke push the ball up court more. Singler seemed to push it off a defensive rebound earlier this season, but stopped. Nolan is the only player to consistently push it off a defenisve stop.


I agree, it would definitely be good to get some more easy transition buckets in there. At the same time though, I like that we haven't been forcing transition plays when none are there (for the most part). Many times come to mind when one of our fast breakers (Jon in particular) saw that we just didn't have the numbers and intelligently slowed down the play to set up the half-court O.

[camion]

I've noticed that we tend to play at a faster tempo against weaker teams. Is this true and how does it affect the ruminations here.

[91_92_01_10_15]

The attached spreadsheet proves statistically that Duke gets more calls in years when they win more games...or is it the other way around?

Anyway, I took the data from the table and put it into a scatterplot. The statiscally generated trendline shows that there is a correlation between wins and fouls (here I've reversed the numbers so that a positive foul disparity means Duke got more calls than the opponents).

On years where the plot point falls to the right of the trendline, you might well think "Duke gets all the calls". And in years where the plot point falls to the right of the trendline, "the refs have it in for Duke".

Note that the years from the mid 80s, early 90s and 2007 fell well to the right of the line, while most of the years after 2001 fall to the left of the line.

Excellent analysis. Thank you. I am distressed to see 2010 depicted as a bit of an outlier. Also distressed to see the trend since 2001.

[77devil]

The stats are interesting, but the foul differentials are for the entire season, and therefore, without comparable data the correlation doesn't really reveal much.

[Chitowndevil]

I am distressed to see 2010 depicted as a bit of an outlier.

Just by eye, it appears that the six largest positive residuals are from 2010, 1998, 2000, 2004, 1986, and 1999. So four Final Fours, a Sweet 16, and the current season. Hardly distressing :)

[hood7]

Interesting analysis (if somewhat over my non-statistically-inclined head). My only question is - How many fouls can you draw when you're shooting 30 three-pointers a game? (ok, that's an exaggeration, but we do shoot a lot of 3s and sometimes 30 or more).

[pfrduke]

Interesting analysis (if somewhat over my non-statistically-inclined head). My only question is - How many fouls can you draw when you're shooting 30 three-pointers a game? (ok, that's an exaggeration, but we do shoot a lot of 3s and sometimes 30 or more).

Percentage of Duke shots that are 3s: 32.8%
National rank: 152nd
3 point attempts on the season: 541
3 point attempts per game: 20.03
# of games we've taken 30 3s: 1

And, just for the heck of it...

3FG%: 39.2%
Points per 3FGA: 1.18
Equivalent 3FG% (each make worth 1.5): 58.8%
2FG%: 47.4%
Points per 2FGA: 0.95

[Acymetric]

Percentage of Duke shots that are 3s: 32.8%
National rank: 152nd
3 point attempts on the season: 541
3 point attempts per game: 20.03
# of games we've taken 30 3s: 1

And, just for the heck of it...

3FG%: 39.2%
Points per 3FGA: 1.18
Equivalent 3FG% (each make worth 1.5): 58.8%
2FG%: 47.4%
Points per 2FGA: 0.95

Of course, the stats for 2 point field goals need to include foul shots that came as a result of 2 point field goal attempts to be more representative of their value. I'm not sure how much of a difference it would make, but certainly it would make a difference.

[pfrduke]

Of course, the stats for 2 point field goals need to include foul shots that came as a result of 2 point field goal attempts to be more representative of their value. I'm not sure how much of a difference it would make, but certainly it would make a difference.

True, although at this point, that's essentially impossible to compile. Hard to tell from the play-by-play data that we have which free throws are off 2 point attempts and which are from off the ball fouls.

That said, going off the back of the envelope, we have 623 FTAs this year, with 473 makes. Let's say 60% (374) come from efforts that would be considered 2-point attempts but for the foul (i.e., missed shot resulting in two free throws) and another 5% (31) come from and-ones, with most of the remaining third being late game or off the ball fouls, and a few sprinkled in for Scheyer getting fouled shooting the 3, technicals, etc.

We make 75.9% of our free throws, so that's ~284 points off the 2-point attempts and another 23-24 off of and-ones.

To factor it in, we have to add the attempted 2-point shot that would have been recorded but for the foul for the first group, which would be 187 attempts (374/2). The last 23 points for and-ones go in for free.

W/o free throws, we got 1056 points on 1110 shots. Adding in the foul shooting, we get 1364 points on 1297 shots, or 1.05 points per attempt. Better, but still not as productive as our 3s.

I'm not suggesting we should just camp out beyond the line and jack up 3s all game. But they're extremely valuable shots that have been used well (and, IMO, in proper proportion) by this team.

[stickdog]

Note that only 4 NCAA players have posted offensive rebounding percentages above 20.0 in any season over the last 5 seasons. Further note that DraftExpress projects Kenneth Faried to be the 10th pick in the second round of the 2010 draft.

Top 20

1 2009 DeJuan Blair, Pittsburgh 23.6
2 2010 Brian Zoubek, Duke 23.0
3 2010 DeMarcus Cousins, Kentucky 22.8
4 2008 Kenneth Faried, Morehead St. 20.2
5 2007 Kentrell Gransberry, South Florida 20.0
6 2006 Boomer Herndon, Belmont 18.7
7 2009 John Bryant, Santa Clara 18.6
8 2005 Hank Rivers, Stephen F. Austin 18.5
9 2007 Joey Dorsey, Memphis 18.3
10 2006 Paul Millsap, Louisiana Tech 18.1
11 2009 Samme Givens, Drexel 18.1
12 2008 Leon Williams, Ohio 18.0
13 2005 Carlton Aaron, Missouri Kansas 17.8
14 2009 Dexter Pittman, Texas 17.7
15 2006 Kenny Adeleke, Hartford 17.6
16 2007 Chris Holm, Vermont 17.4
17 2008 Jason Love, Xavier 17.4
18 2009 Tracy Smith, North Carolina St. 17.4
19 2010 Anthony Johnson, Fairfield 17.4
20 2007 Jason Hopkins, Lipscomb 17.3

Selected other players

27 2005 Sean May, North Carolina 16.6
28 2008 DeJuan Blair, Pittsburgh 16.6
33 2006 Kevin Young, Missouri 16.4
37 2010 Alex Stepheson, Southern California 16.3
38 2005 Andrew Bogut, Utah 16.1
40 2010 Dexter Pittman, Texas 16.1
41 2005 Lance Allred, Weber St. 16.0
43 2005 Paul Millsap, Louisiana Tech 15.8
46 2010 Artsiom Parakhouski, Radford 15.8
48 2006 Aaron Gray, Pittsburgh 15.7
50 2010 Kenneth Faried, Morehead St. 15.7
57 2009 Jon Brockman, Washington 15.6
65 2005 Jason Fraser, Villanova 15.4
68 2006 Joey Dorsey, Memphis 15.4
72 2008 Kevin Love, UCLA 15.4
74 2009 Jordan Hill, Arizona 15.4
77 2007 Jon Brockman, Washington 15.3
84 2008 Joey Dorsey, Memphis 15.2
87 2010 Dwayne Collins, Miami FL 15.2
89 2010 Al-Farouq Aminu, Wake Forest 15.2
90 2010 Corey Raji, Boston College 15.2
91 2006 Roy Hibbert, Georgetown 15.1
96 2005 Taj Gray, Oklahoma 15.0
98 2008 Jon Brockman, Washington 15.0
102 2005 Kevin Young, Missouri 14.9
108 2007 Luke Harangody, Notre Dame 14.8
109 2007 Aaron Gray, Pittsburgh 14.8
116 2007 Greg Oden, Ohio St. 14.7
122 2006 Glen Davis, Louisiana St. 14.6
124 2007 Roy Hibbert, Georgetown 14.6

"The good news is that I haven't been in this situation very often." Roy Williams, unbroken by losing

[Bob Green]

The remainder of February, all of March, and hopefully early April, is going to be extremely important for Brian Zoubek. He is going to be playing his heart out for the Duke Blue Devils, and I'm sure that is most important to him, but make no mistake, NBA scouts and general managers will be paying attention so Zoubek will simultaneously be displaying his resume for the June draft. He is 7'1" 260 and has been mobile in recent games. If he keeps chasing down those rebounds, folks who matter are going to be impressed.

[OZZIE4DUKE]

The remainder of February, all of March, and hopefully early April, is going to be extremely important for Brian Zoubek. He is going to be playing his heart out for the Duke Blue Devils, and I'm sure that is most important to him, but make no mistake, NBA scouts and general managers will be paying attention so Zoubek will simultaneously be displaying his resume for the June draft. He is 7'1" 260 and has been mobile in recent games. If he keeps chasing down those rebounds, folks who matter are going to be impressed.
You can't teach height! But you can teach someone who has height!

[91_92_01_10_15]

Just by eye, it appears that the six largest positive residuals are from 2010, 1998, 2000, 2004, 1986, and 1999. So four Final Fours, a Sweet 16, and the current season. Hardly distressing :)

Thanks for the positive spin.

[GODUKEGO]

Zoub has 186 rebounds with (50%) 93 coming offensively. In the VA Tech game, I never saw him so aggressively go after the ball. He was determined. Keep it up, Brian the Beast.
Attached are stats for offensive rebounds. Zoub is averaging 16.3 minutes a game. Notice below the stat of games started, 3. I know you have to be careful with stats but if he was averaging 32 minutes a game which is probably about average for a starter, if you doubled the 93 he would be the BEAST. Stay out of foul trouble, watch the illegal screens and no fouls more than 15 feet from the basket.

http://feeds.foxsports.com/cbk/sortableStats?div=99&table=defense&stat=oReb&dir=descending

[Chitowndevil]

Based on the last post I looked up the tempo free stats. It's been noted elsewhere that Zoubek leads the country in OR% (percentage of missed FGA/FTA rebounded) with 23%.

Because of this, perhaps more surprisingly, Zoubek's tempo-free Offensive rating (roughly speaking, points generated per 100 possessions) is 116.5, 163rd in the country, and 3rd on the team behind Sheyer's 130.7 (!!), Nolan's 117.5, and just in front of Kyle's 114.3.

[Neals384]

Note that only 4 NCAA players have posted offensive rebounding percentages above 20.0 in any season over the last 5 seasons. Further note that DraftExpress projects Kenneth Faried to be the 10th pick in the second round of the 2010 draft.

Top 20

1 2009 DeJuan Blair, Pittsburgh 23.6
2 2010 Brian Zoubek, Duke 23.0
3 2010 DeMarcus Cousins, Kentucky 22.8


As tough a rebounder as he is, Blair picked up a lot of his o-boards by violating the 3 second rule. And never got called for it.

[mehmattski]

The attached spreadsheet proves statistically that Duke gets more calls in years when they win more games...or is it the other way around?

Anyway, I took the data from the table and put it into a scatterplot. The statiscally generated trendline shows that there is a correlation between wins and fouls (here I've reversed the numbers so that a positive foul disparity means Duke got more calls than the opponents).

On years where the plot point falls to the right of the trendline, you might well think "Duke gets all the calls". And in years where the plot point falls to the right of the trendline, "the refs have it in for Duke".

Note that the years from the mid 80s, early 90s and 2007 fell well to the right of the line, while most of the years after 2001 fall to the left of the line.

Great post! I agree with other folks in a fairly simple interpretation of the trend: better teams get fouled more than they foul, due to things like better positioning on defense, quicker ball handlers, more skill under the basket. Some of the best teams in Coach K's reign are at the right side of the graph: 1999, 2001, 1992, while the worst teams are on the left side (1995, 1982, 1983).

As the author of the linked article I must say I am very pleased with how well everyone seems to be taking to the tempo-free stats. DBR is truly full of a unique set of fans! I definitely agree that the keys to a long run in March will be reducing opponents' 2pt%, and getting to the line a little more to take advantage of the great FT%. The game against VT was a perfect example of that: if the shooting is cold, rely on your offensive rebounders and driving to the bucket looking for a layup or foul.