Logarithmic Decay in the NFL Draft: Do Busts Matter?

Welcome back for Part 2 of my pre-draft stat series wherein I attempt to test my own theories about the importance of avoiding busts and finding diamonds in the rough. In Part 1, I took a stab at developing objective definitions for "bust" and "diamond in the rough." Based on an analysis of all NFL draft picks from 1994-2005, the definitions I arrived at were as follows:

  • An NFL draft bust is a player who was selected in the 1st or 2nd round and played 67% or more below the expected performance of his specific pick number.
  • An NFL draft diamond in the rough is a player who was selected after the 2nd round and played 200% or more above the expected performance of his specific round.

Today in Part 2, I'll be focusing on busts (insert juvenile humor here). Specifically, I'll be telling you who the biggest busts of the 1st and 2nd rounds were from 1994-2005, tell you how each team has done with respect to avoiding busts, and finally answer the question, "Do good teams avoid picking busts?" Given that this is Niners Nation, I'll be focusing especially on how the 49ers have fared bust-wise.

After the jump, I dive deep into the anatomy of busts... 

PHANTOM BUST

Before I get started, I just want to rehash an issue that arose during Part 1; namely, the uncertainty about whether specific pick numbers matter. I think I pretty convincingly showed that they matter for picks in Rounds 1 and 2, but two issues make me feel like I need a qualifier in my bust definition:

  1. The logarithmic decay function did a better job of explaining draft pick performance when I used rounds rather than picks.
  2. The trendline for my pick-by-pick analysis, although awesomely predictive overall, did worst at the top of the draft (i.e., Round 1).

So, with this kind of conflicting evidence about the correct equation to use, I'm going to call pre-flop rather than pushing all-in. That is, I'm going to create a 2nd, less-pick-dependent class of busts, which I'll call "mild busts." These mild busts are players who played 50% or more below the expected performance of his pick number, which is slightly better than the 67% underachievement exhibited by full-on, no-doubt-about-it busts in my definition.

ATTACK OF THE BUSTS

Excluding 2 Ks and 1 P, there were a total of 748 total picks in the 1st and 2nd rounds from 1994-2005. Of these 748 picks, 70 of them were full-on busts, and another 40 were mild busts, which adds up to a total of 110 total busts, or 14.7%. Given how much people like to describe the draft as a crapshoot, I think that a non-bust rate of 85.3% is pretty darn good and suggests that NFL GMs actually know what they're doing for the most part. After all, 14.7% translates into about 1 bust every 6 picks.

Looking at individual rounds, there have been only 25 full-on busts among the 370 picks from 1994-2005, for a bust rate (BR) of 6.8%. Again, given the volume of bust-related discussion around water coolers and message boards, you'd think that percentage would be way higher. If you had in the mild busts, the NFL BR in Round 1 increases to 11.1%, which is still not too shabby.

Either way, we're talking about 1 full-on bust for every 7 first-round picks or 1 overall bust for every 10 first-round picks. Alternatively, we're talking about between 2 and 4 first-round busts per draft (depending on whether you include the mild ones). I'd venture to guess that that's far fewer than most people assume. I think, given the commentary, it seems like most fan bases consider their team's first-round pick a bust unless he becomes the next Peyton Manning.

REVENGE OF THE BUSTS

So who was the cream of the bust crop from 1994-2005? Who were the busts to end all busts? Below is a table showing the Top 20 1st-round busts during that period:

Top 20 First-Round Busts

Rk

Player

Year

Pk

Pos

Tm

NFL Yrs

AV Avg

Exp AV Avg

Under

1

Andre T. Johnson

1996

30

T

WAS

2

0.00

3.84

100.0%

2

Akili Smith

1999

3

QB

CIN

4

0.25

7.12

96.5%

3

Craig Powell

1995

30

LB

BAL

4

0.25

3.84

93.5%

4

Reggie McGrew

1999

24

DT

SF

3

0.33

4.16

92.0%

5

Trezelle Jenkins

1995

31

T

KC

3

0.33

3.80

91.2%

6

Ryan Leaf

1998

2

QB

SD

4

0.75

7.70

90.3%

7

Jerome McDougle

2003

15

DE

PHI

6

0.50

4.83

89.6%

8

Jamal Reynolds

2001

10

DE

GB

3

0.67

5.41

87.7%

9

Jim Druckenmiller

1997

26

QB

SF

2

0.50

4.05

87.6%

10

Dimitrius Underwood

1999

29

DT

MIN

2

0.50

3.89

87.1%

11

Marcus Nash

1998

30

WR

DEN

2

0.50

3.84

87.0%

12

Ki-Jana Carter

1995

1

RB

CIN

9

1.33

8.68

84.6%

13

John Avery

1998

29

RB

MIA

6

0.67

3.89

82.9%

14

Charles Rogers

2003

2

WR

DET

3

1.33

7.70

82.7%

15

Willie Middlebrooks

2001

24

DB

DEN

5

0.80

4.16

80.8%

16

Heath Shuler

1994

3

QB

WAS

4

1.75

7.12

75.4%

17

Wendell Bryant

2002

12

DT

ARI

3

1.33

5.15

74.1%

18

Trev Alberts

1994

5

LB

IND

3

1.67

6.39

73.9%

19

Rashaun Woods

2004

31

WR

SF

1

1.00

3.80

73.7%

20

Troy Williamson

2005

7

WR

MIN

5

1.60

5.91

72.9%

As always, some housekeeping first. In the table, AV Avg basically translates as actual career performance, whereas Exp AV Avg is what performance was expected given that player's pick number (Pk). The Under category tells you how much the player underachieved performance expectations.

At first glance, what jumps out to me is the fact that the 49ers had 3 of the Top 20 busts, and 2 of the Top 10. Also, they stand out as the only team to have selected a player that busted out after only 1 season in the NFL.

Oh, and one other thing of note about the Niners' busts. Each draft regime got in on the Top-20 bust party. Druckenmiller was taken by the Policy regime, McGrew was taken by the 2nd Walsh regime, and Woods was taken by the Donahue regime. To boot, if we expanded this out to include all busts (full-on or mild), it would be 4 for 4: Alex Smith (taken by the McNolan regime), has been a mild bust thus far in his career; ranking 27th with an underachievement rate of 63.1%.

A NEW BUST

Now let's move to Round 2. Below is a table showing the Top 20 second-round busts from 1994-2005:

Top 20 Second-Round Busts

Rk

Player

Year

Pk

Pos

Tm

NFL Yrs

AV Avg

Exp AV Avg

Under

1

Leon Bender

1998

31

DT

OAK

0

0.00

3.80

100.0%

2

Nathan Davis

1997

32

DE

ATL

3

0.00

3.75

100.0%

3

Charles Fisher

1999

33

DB

CIN

1

0.00

3.71

100.0%

4

James Manley

1996

45

DT

MIN

1

0.00

3.27

100.0%

5

Israel Ifeanyi

1996

46

DE

SF

1

0.00

3.23

100.0%

6

Paul Toviessi

2001

51

DE

DEN

0

0.00

3.09

100.0%

7

Pat Riley

1995

52

DE

CHI

1

0.00

3.06

100.0%

8

Jacob Rogers

2004

52

T

DAL

1

0.00

3.06

100.0%

9

Dan Cody

2005

53

DE

BAL

1

0.00

3.03

100.0%

10

Eric Shelton

2005

54

RB

CAR

1

0.00

3.01

100.0%

11

Michael Boireau

2000

56

DE

MIN

0

0.00

2.95

100.0%

12

Terrence Murphy

2005

58

WR

GB

1

0.00

2.90

100.0%

13

Jimmy Oliver

1995

61

WR

SD

0

0.00

2.83

100.0%

14

Jesse James

1995

62

C

STL

2

0.00

2.81

100.0%

15

Shane Hannah

1995

63

G

DAL

0

0.00

2.79

100.0%

16

Marquise Hill

2004

63

DE

NE

3

0.00

2.79

100.0%

17

Marques Tuiasosopo

2001

59

QB

OAK

8

0.13

2.88

95.7%

18

Alex Van Dyke

1996

31

WR

NYJ

5

0.20

3.80

94.7%

19

Andrew Greene

1995

53

G

MIA

4

0.25

3.03

91.8%

20

Jacoby Shepherd

2000

62

DB

STL

4

0.25

2.81

91.1%

As you can see, almost all of the Top 20 consists of players who literally added no value to their teams during their careers. Furthermore, 5 of the Top 20 never even played a single game in their NFL careers. I don't know what's worse: playing 0 years or playing 1 or more years without ever adding any value to your team. For the sake of simplicity, I ranked all those 100% underachievement guys in descending order of Exp AV Avg.

As far as the 49ers go, they're far less prominent in the 2nd-round bust list: only 1 of the Top 20, and only 1 bust total (full-on or mild). Rather than the Niners, the team that stands out to me here is their cross-town NFL-mates, the Oakland Raiders. Specifically, they treated their massive busts very differently. Whereas they took the #1 2nd-round bust from 1994-2005, a DT who ended up never playing for them, they also took the #17 bust, but he ended up playing 8 seasons for them. Go figure. I think Marques Tuiasosopo was the Raider equivalent of Arnaz Battle in that I find myself wondering, "How did he stay on their roster for that long?"

THE BUST STRIKES BACK

Although that's a question I often ask myself, the one that I'm specifically here to answer is, "Do busts matter?" That is, do good teams do a good job of avoiding busts? To find that out, I tallied up all the busts for each team, got their winning percentages from 1994-2009, and calculated the league-wide correlations of winning percentage to (a) total busts, and (b) BR. Below is a table showing every team's bust totals along with the league-wide totals and correlations:

Team

Win Pct

Pks1

Pks2

Tot Pks

FB1

TB1

FB2

TB2

FB

TB

MIN

0.566

16

15

31

3

3

2

7

5

10

CIN

0.393

13

12

25

3

5

1

2

4

7

KC

0.508

10

9

19

1

2

3

4

4

6

SF

0.520

13

12

25

3

5

1

1

4

6

ARI

0.391

13

14

27

1

2

3

3

4

5

CHI

0.469

11

11

22

0

2

2

3

2

5

MIA

0.523

8

12

20

2

3

1

2

3

5

PIT

0.627

12

11

23

0

2

2

3

2

5

BUF

0.469

11

15

26

1

2

2

2

3

4

DAL

0.547

8

17

25

0

0

3

4

3

4

DEN

0.598

9

13

22

2

2

2

2

4

4

DET

0.344

15

12

27

1

2

1

2

2

4

NYJ

0.465

13

10

23

0

0

2

4

2

4

TEN

0.535

10

14

24

0

1

2

3

2

4

BAL

0.518

15

9

24

1

1

1

2

2

3

GB

0.625

12

7

19

1

1

2

2

3

3

NE

0.641

14

13

27

0

0

2

3

2

3

NYG

0.521

11

12

23

0

1

1

2

1

3

OAK

0.414

14

12

26

0

0

2

3

2

3

PHI

0.566

12

16

28

1

1

0

2

1

3

STL

0.430

15

15

30

0

1

2

2

2

3

WAS

0.439

12

8

20

2

2

1

1

3

3

ATL

0.471

9

10

19

1

1

1

1

2

2

CAR

0.488

12

11

23

0

0

2

2

2

2

NO

0.449

12

12

24

0

0

1

2

1

2

SD

0.508

7

18

25

1

1

1

1

2

2

SEA

0.500

15

11

26

0

0

0

2

0

2

HOU

0.383

5

3

8

0

0

1

1

1

1

IND

0.625

12

12

24

1

1

0

0

1

1

JAC

0.521

13

14

27

0

0

1

1

1

1

CLE

0.335

7

8

15

0

0

0

0

0

0

TB

0.496

11

10

21

0

0

0

0

0

0

Total

--

370

378

748

25

41

45

69

70

110

r(Win Pct)

--

0.084

0.243

0.219

0.070

-0.010

0.110

0.204

0.129

0.130

More housekeeping. Pks1 and Pks2 are the total number of picks each team had in Rounds 1 and 2, respectively. FB stands for "full-on busts" and is the total number of full-on busts for each team, whereas TB stands for "total busts" and is the total number of busts (full-on plus mild) for each team. I've listed the teams in descending order of total busts.

Looking at the correlations, you can see that my theory is basically destroyed when it comes to totals. The only totals that are even remotely associated with winning percentage are (a) total # of 2nd-round picks, (b) total number of combined 1st- and 2nd-round picks, and (c) total busts in the 2nd round. Of course, the problem here is that these 3 are all positive correlations, meaning that, as the total goes up, so does winning percentage. So if anything, as it relates to busts, it turns out that we can venture to say that total busts don't matter, but winning is associated with selecting more 2nd-round busts. Obviously, that makes no sense. In other words, epic theory fail.

RETURN OF THE BUST

What about bust rates (BRs)? Maybe it's not the totals that matter, but rather the rate at which a team selects busts. Do teams that waste a higher percentage of their 1st- and 2nd-round picks on busts lose more than teams that avoid such a fate? Below is the relevant table, which is the same as the one above except it substitutes rates for totals:

Team

Win Pct

FBR1

TBR1

FBR2

TBR2

FBR

TBR

MIN

0.566

18.8%

18.8%

13.3%

46.7%

16.1%

32.3%

KC

0.508

10.0%

20.0%

33.3%

44.4%

21.1%

31.6%

CIN

0.393

23.1%

38.5%

8.3%

16.7%

16.0%

28.0%

MIA

0.523

25.0%

37.5%

8.3%

16.7%

15.0%

25.0%

SF

0.520

23.1%

38.5%

8.3%

8.3%

16.0%

24.0%

CHI

0.469

0.0%

18.2%

18.2%

27.3%

9.1%

22.7%

PIT

0.627

0.0%

16.7%

18.2%

27.3%

8.7%

21.7%

ARI

0.391

7.7%

15.4%

21.4%

21.4%

14.8%

18.5%

DEN

0.598

22.2%

22.2%

15.4%

15.4%

18.2%

18.2%

NYJ

0.465

0.0%

0.0%

20.0%

40.0%

8.7%

17.4%

TEN

0.535

0.0%

10.0%

14.3%

21.4%

8.3%

16.7%

DAL

0.547

0.0%

0.0%

17.6%

23.5%

12.0%

16.0%

GB

0.625

8.3%

8.3%

28.6%

28.6%

15.8%

15.8%

BUF

0.469

9.1%

18.2%

13.3%

13.3%

11.5%

15.4%

WAS

0.439

16.7%

16.7%

12.5%

12.5%

15.0%

15.0%

DET

0.344

6.7%

13.3%

8.3%

16.7%

7.4%

14.8%

NYG

0.521

0.0%

9.1%

8.3%

16.7%

4.3%

13.0%

BAL

0.518

6.7%

6.7%

11.1%

22.2%

8.3%

12.5%

HOU

0.383

0.0%

0.0%

33.3%

33.3%

12.5%

12.5%

OAK

0.414

0.0%

0.0%

16.7%

25.0%

7.7%

11.5%

NE

0.641

0.0%

0.0%

15.4%

23.1%

7.4%

11.1%

PHI

0.566

8.3%

8.3%

0.0%

12.5%

3.6%

10.7%

ATL

0.471

11.1%

11.1%

10.0%

10.0%

10.5%

10.5%

STL

0.430

0.0%

6.7%

13.3%

13.3%

6.7%

10.0%

CAR

0.488

0.0%

0.0%

18.2%

18.2%

8.7%

8.7%

NO

0.449

0.0%

0.0%

8.3%

16.7%

4.2%

8.3%

SD

0.508

14.3%

14.3%

5.6%

5.6%

8.0%

8.0%

SEA

0.500

0.0%

0.0%

0.0%

18.2%

0.0%

7.7%

IND

0.625

8.3%

8.3%

0.0%

0.0%

4.2%

4.2%

JAC

0.521

0.0%

0.0%

7.1%

7.1%

3.7%

3.7%

CLE

0.335

0.0%

0.0%

0.0%

0.0%

0.0%

0.0%

TB

0.496

0.0%

0.0%

0.0%

0.0%

0.0%

0.0%

Average

--

6.8%

11.1%

11.9%

18.3%

9.4%

14.7%

r(Win Pct)

--

0.106

0.042

0.011

0.106

0.096

0.117

I've listed teams in this table in descending total-bust-rate (TBR) order.

Looking again at the correlations, it's an even bigger epic theory fail. Clearly, busts don't matter; even when we're talking about them as a percentage of total bust-selecting opportunities. Also clear is that I'm going to start having to polish off my apology lines as promised.

BOTTOM LINE

Based on what I've presented in Part 2, here's what you should take away going into tonight's draft:

  1. There aren't as many busts selected in the NFL as you think there are.
  2. Whereas a team's 1st-round pick is almost guaranteed to play one day for them, the NFL graveyard is littered with 2nd-round picks who never even played a down.
  3. The Niners sucked immensely from 1994-2005 when it came to avoiding busts, but...
  4. Avoiding busts doesn't matter when it comes to winning in the NFL.

Stay tuned for Part 3 sometime tomorrow, wherein I'll pray that the diamond in the rough part of my theory doesn't suffer the same fate as the bust part did.

p.s. There was a lot more I could have discussed here, but time is of the essence. The draft is nigh, so feel free to continue the discussion in the comments section.

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