Saturday, February 2, 2013

A More Honest Way to Evaluate

My goal in writing here at Pitcher’s Duel is to grow as a writer and baseball fan. I probably still won’t be able to write very well, but I will be making an improvement as a fan in 2013. 

One improvement is abandoning per-inning stats such as K/9 or BB/9 in favor of the more telling per-PA stats like K% and BB%. I give 100% credit to Joe Sheehan of Sports Illustrated for illuminating the difference, but it cannot be understated. Per-inning numbers operate under the assumption that each pitcher faces the same amount of batters each inning – or, at least, that is the assumption we make in using these figures. Given a moment’s pause, it’s obvious this assumption is lazy and leaves out a significant chunk of the information.

A prime example of the difference in 2012 is the contrast of Tim Lincecum and Cliff Lee. Using K/9, Lincecum bests Lee by a significant margin – 9.19 to 8.83. However, while looking at K%, Lee is clearly the more strikeout friendly pitcher – 24.4% to 23%. The difference stems from Lee being a more efficient pitcher, yet that doesn’t come through using K/9. K% gives a more honest appraisal of a player’s skill than it’s counterpart.

I will admit I have been slow to make this change. I have been so comfortable with the scale on which K/9 (and similar numbers) operates and learning the nuances of K% (and similar numbers) seems a bit tedious. To try to familiarize myself, and hopefully you, to the system I’ll be using in the future, I thought it would be helpful to look at some of last season’s benchmarks:

All stats from FanGraphs. Thanks FG, you rule.

K% Starting Pitchers (88 qualified)
#1) Max Scherzer – 29.4%
25th Percentile) Matt Cain – 22%
50th Percentile) Jered Weaver – 19.2%
75th Percentile) Kyle Lohse – 16.6%
Last) Henderson Alvarez – 9.8%

BB% Starting Pitchers
#1) Cliff Lee – 3.3%
25th Percentile) Matt Cain – 5.8 %
50th Percentile) Matt Harrison - 6.7%
75th Percentile) Jarrod Parker – 8.4%
Last) Edinson Volquez – 13.1%

K% Relievers (136 qualified)
#1) Craig Kimbrel – 50.2% (!!!)
25th Percentile) Tom Wilhelmson - 26.7%
50th Percentile) Josh Lindblom – 23%
75th Percentile) Jon Broxton - 18.9%
Last) Jeff Gray -11%

BB% Relievers
#1) Wilton Lopez – 3.1%
25th Percentile) Joel Peralta – 6.4%
50th Percentile) Vinnie Pestano – 8.4%
75th Percentile) Jordan Norberto – 10.4%
Last) Carlos Norberto – 18.2%

K% Hitters (143 qualified)
#1) Marco Scutaro – 7.2%
25th Percentile) Joe Mauer – 13.7%
50th Percentile) Ryan Doumit – 18.6%
75th Percentile) Alex Rodriguez – 21.9%
Last) Adam Dunn – 34.2%

BB% Hitters
First) Adam Dunn – 16.2%
25th Percentile) Matt Wieters – 10.1%
50th Percentile) Denard Span – 8.3%
75th Percentile) Jose Altuve – 6.3%
Last) Alexei Ramirez – 2.6%


Hopefully this introduction was somewhat convincing or at least helps familiarize, because it won't be the last time it comes up. 

Here's to a more honest 2013.

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