We can easily look up a Team's DER (Defense Efficiency Rating) from several websites. However, I wondered how it varied from pitcher to pitcher within a team. So I took a quick look first at the the 2010 Reds. And next I compared the DER of Bronson Arroyo and Aaron Harang, since they have both pitched a large number of innings with basically the same fielders behind them for the past five seasons.
I used my own DER formula and will explain it briefly:
1) Take IP and multiply by 3 to get the total number of outs needed.
2) Subtract strikeouts to get the total number of fielding outs needed.
3) Take PA and subtract out (HR+K+BB+HBP) (things that are out of the control of fielders) to get actual fielding chances.
4) Divide number of fielding outs needed by number of actual fielding chances.
Okay that is out of the way. So what were the results?
First the 2010 Reds' Pitchers DER:
Here is the chart comparing Arroyo and Harang over the years.Code:ERA PDER10 Travis Wood 2.65 0.801 Bronson Arroyo 3.94 0.798 Johnny Cueto 3.38 0.752 CoCo Cordero 4.03 0.745 Mike Leake 4.16 0.743 Homer Bailey 5.51 0.716 Aaron Harang 5.02 0.706 Nick Masset 4.13 0.701
Here are the Reds Team DER from 2006-2010 as sort of a baseline to go on. Note how much improvement there has been in the past two years.Code:ERA PDER ERA PDER BA06 3.29 0.758 AH06 3.76 0.710 BA07 4.23 0.718 AH07 3.73 0.741 BA08 4.77 0.722 AH08 4.78 0.722 BA09 3.94 0.772 AH09 4.21 0.703 BA10 3.84 0.798 AH10 5.02 0.706 BA-TOT 0.752 AH-TOT 0.718
This, obviously is a very small sample, but maybe it suggests that pitchers that work faster get better fielding support behind them.Code:YEAR TDER 2006 0.725 2007 0.723 2008 0.721 2009 0.759 2010 0.753
In any case since I had it already had it on Excel I went ahead and posted it in case anyone was interested.
If anyone was wondering why my DER differs from the DER you find on various websites it is because, in short, I think mine is better. Here is a typical definition of DER from The Hardball Times: Defense Efficiency Ratio.That is all well and good up to a point, IMO. But it doesn't take into account things that a defense can do that can make a huge difference. Those types of things include outfield assists, caught stealing, pickoffs, double plays and cutting down runners on the basepaths. I just took the view that if a defense needed to get X amount of outs in a season, the team that took fewer batters to get those required outs was the better defense.Code:The percent of times a batted ball is turned into an out by the teamsí fielders, not including home runs.