Checking Historical Trends with Vance Worley

On July 18, I posted what I thought were reasonable expectations of Vance Worley going forward. I compared the start to his Major League career to that of J.A. Happ, noting the many similarities between the two. In the ensuing two weeks, Worley continued to have success, throwing eight innings of one-run baseball against the Chicago Cubs in the sweltering heat, and tossing a complete game against the San Francisco Giants at home.

As a result, Worley was crowned the next DIPS-defiant pitcher. Despite a sub-.240 BABIP and strikeout and walk rates that were good but not good enough to merit a 2.02 ERA, Worley just couldn’t be captured by ERA retrodictors. Worley had a rare mediocre outing against the Pittsburgh Pirates on Sunday, allowing four runs in six innings. While that is neither confirmation nor denial of anything, it was an example of what should be expected of the right-hander moving forward.

Due to the complexity of stats like SIERA, some people will be forever skeptical. For those people, I would like to instead illustrate the matter using historical data from pitchers who posted numbers similar to Worley in a single season. Using Baseball Reference’s Play Index, I searched 2000-10 for ERA-title-qualified pitchers that started 80 percent of their games with a K/9 below 7.0 and BABIP below .250. The results:

Rk Player ERA SO/9 BAbip Year Age Tm GS
1 Derek Lowe 2.58 5.20 .237 2002 29 BOS 32
2 Trevor Cahill 2.97 5.40 .237 2010 22 OAK 30
3 Joe Mays 3.16 4.74 .246 2001 25 MIN 34
4 Al Leiter 3.21 6.06 .244 2004 38 NYM 30
5 Mark Buehrle 3.29 5.12 .245 2001 22 CHW 32
6 Barry Zito 3.30 5.67 .242 2003 25 OAK 35
7 Jamie Moyer 3.32 5.74 .246 2002 39 SEA 34
8 Damian Moss 3.42 5.58 .238 2002 25 ATL 29
9 Joe Blanton 3.53 5.19 .249 2005 24 OAK 33
10 Ryan Franklin 3.57 4.20 .248 2003 30 SEA 32
11 Armando Galarraga 3.73 6.35 .237 2008 26 DET 28
12 Ramon Ortiz 3.77 6.71 .239 2002 29 ANA 32
13 Barry Zito 3.86 6.74 .246 2005 27 OAK 35
14 Bronson Arroyo 3.88 5.05 .241 2010 33 CIN 33
15 Tim Wakefield 4.13 5.82 .240 2008 41 BOS 30
16 David Bush 4.18 5.30 .238 2008 28 MIL 29
Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 8/1/2011.

Certainly some recognizable players there, including many pitchers who went on to have long, productive Major League careers. But most of them fall on the wrong side of “average”.

How did those pitchers fare in the following year?

(nyERA stands for Next Year ERA and nyE-ERA is the difference between nyERA and ERA)

Player

ERA

Year

nyERA

nyE-ERA

Leiter

3.21

2004

6.13

2.92

Mays

3.16

2001

5.38

2.22

Bush

4.18

2008

6.38

2.20

Galarraga

3.73

2008

5.64

1.91

Lowe

2.58

2002

4.47

1.89

Moss

3.42

2002

5.16

1.74

Arroyo

3.88

2010

5.58

1.70

Ortiz

3.77

2002

5.20

1.43

Franklin

3.57

2003

4.90

1.33

Blanton

3.53

2005

4.82

1.29

Zito

3.3

2003

4.48

1.18

Cahill

2.97

2010

3.58

0.61

Wakefield

4.13

2008

4.58

0.45

Buehrle

3.29

2001

3.58

0.29

Zito

3.86

2005

3.83

-0.03

Moyer

3.32

2002

3.27

-0.05

For those of you who process information better visually (click to enlarge):

All but two pitchers regressed, and those two barely didn’t regress. 11 of the 16 pitchers regressed by more than one run in ERA. The big reason was that their BABIP normalized. Pitchers don’t have much control over BABIP, so it will regress back to .300 the overwhelming majority of the time. Worley’s BABIP is currently 45 points below the league average.

There are pitchers out there, like Matt Cain, that DIPS doesn’t analyze properly. Those pitchers, however, are few and far between. Furthermore, it is nearly impossible to identify them without multiple seasons of data. Despite all of my negative prognostications of Worley, it still remains possible that he is the next DIPS-defiant pitcher. It is extremely unlikely, though, given all of the information presently available that say otherwise.