DRB contributor Matthan has done some very comprehensive work on the performance of pitchers in year 1 and year 2 under the direction of pitching coach Jim Hickey. He came to the conclusion that there is a strong statistical evidence of a decline in pitchers'' K/9 under Hickey. The next step is establishing why. Is it intentional? If so, how come?
For my numbers, I divided the pitchers into 2 groups based on the number of innings pitched. Over 100 IP in each year crowned you a starter. One pitcher, Brandon Backe, was thrown out for being over 100 and under 100 (injury). In total, there were 10 relievers and 8 starters. This field of pitchers comes from the 2005 and 2006 Astros and the 2007 and 2008 Rays. The starters are divided evenly between the teams while 6 of the 10 relief pitchers came from the Rays.
The metrics I looked at were strikeouts per nine innings, unintentional walks per nine innings, strikeout percentage of total batters faced, strikeout to walk ratio, pitches per inning, and strike %. I looked at each pitcher's change from year 1 to year 2 under Hickey, the average change per pitcher, and the change in the total performance of the group (For example K/9 would be combined strikeouts / combined innings * 9).
Below is the data of the changes. The hard #'s are available on the google spreadsheet at the end of the article:
Starters
Player |
K/9 |
uBB |
K% |
K/uBB |
P/Inn |
Strike% |
Andy Pettitte |
0.55 |
0.9 |
-0.38% |
-1.25 |
1.91 |
-2.31% |
Roger Clemens |
0.22 |
-0.2 |
0.54% |
0.4 |
0.93 |
-0.65% |
Roy Oswalt |
-0.08 |
-0.29 |
0.16% |
0.79 |
-0.15 |
0.26% |
Wandy Rodriguez |
0.91 |
0.15 |
1.75% |
0.18 |
0.63 |
0.38% |
Andy Sonnanstine |
-0.91 |
-0.02 |
-2.37% |
-0.5 |
-0.94 |
1.01% |
Edwin Jackson |
-1.85 |
-1.02 |
-3.32% |
-0.08 |
-1.75 |
1.21% |
James Shields |
-1 |
0.17 |
-2.81% |
-1.11 |
-0.21 |
-1.27% |
Scott Kazmir |
-0.6 |
0.19 |
-1.05% |
-0.27 |
0.59 |
-0.28% |
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Average Change |
-0.35 |
-0.02 |
-0.93% |
-0.23 |
0.13 |
-0.21% |
Group Change |
-0.57 |
-0.02 |
-1.67% |
-0.2 |
0.13 |
-0.19% |
Notice there is a strong difference between the ballclubs. All four of the Rays starters had significant declines in K% and K/9 while also throwing fewer pitches per inning outside of Scott Kazmir. Its probably worth looking into pitches/plat appearance also. Both the Astros and Rays had improved defenses in their second year. In the case of the Rays, it was a conscious effort to upgrade defensively. The Astros UZR/150 jumped from 2.9 to 6.1. However Batting Average on Balls in Play went up from .289 to .294. The Rays UZR jumped from a MLB worst -6.5 to an MLB best 11. As you would expect their BABIP fell from .338 to .285. This large a decline in BABIP would have an unavoidable drop in K/9 all things being equal, but K% should remain unaffected. However, if pitchers were pitching to contact, their walks would decrease as well.
There is also the chance there is much deeper strategy. Perhaps, the Rays decided to go aggressively after players with low slugging due to their defense, while at the same time pitching around sluggers more than the average team due to their faith in the defense helping to strand the runners. There is no way to draw any conclusions at this point without tying other metrics into the equation. The next stats to look at in my opinion would be first strike%, evaluating the characteristics of the batters being walked, and pitches/plate appearance. Comparisons of teams with similar defensive improvements also might be worth a look.
The more collaborative this effort is, the better the results will be. I look forward to your feedback and improvements.
Below is the relief matrix. I am struggling to do much with this due to the smaller inning samples and the greater variance.
Player |
K/9 |
uBB |
K% |
K/uBB |
P/Inn |
Strike% |
Brad Lidge |
-0.63 |
1.04 |
-4.81% |
-1.43 |
1.92 |
-4.39% |
Chad Qualls |
-1.09 |
-0.14 |
-2.51% |
-0.31 |
-0.66 |
-1.21% |
Dan Wheeler |
0.11 |
0.06 |
-0.91% |
-0.06 |
1.61 |
-3.52% |
Russ Springer |
-1.3 |
-0.48 |
-2.78% |
0.07 |
-1.06 |
1.29% |
Al Reyes |
-2.85 |
0.21 |
-7.77% |
-1.13 |
-0.17 |
-0.31% |
Dan Wheeler |
-2.17 |
-0.44 |
-2.34% |
-0.31 |
-3.14 |
0.23% |
Gary Glover |
-0.11 |
0.65 |
-1.52% |
-0.43 |
2.2 |
-0.67% |
Grant Balfour |
1.61 |
-2.99 |
10.39% |
1.88 |
-3.61 |
2.15% |
J.P. Howell |
0.63 |
0.12 |
4.78% |
0.09 |
-2 |
1.31% |
Jason Hammel |
-1.72 |
-0.57 |
-3.95% |
-0.22 |
-1.92 |
0.05% |
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Average Change |
-0.75 |
-0.25 |
-1.14% |
-0.19 |
-0.68 |
-0.51% |
Group Change |
-0.35 |
-0.04 |
-0.36% |
-0.08 |
-0.53 |
-0.72% |