Tuesday, June 4, 2013

Sabermetric Special- Defense-Independent Pitching Statistics (DIPS)




Hey hey, let’s look at this week’s sabermetric special on Defense-Independent Pitching Statistics (DIPS).

DIPS measures a pitcher’s value or effectiveness based on statistics that does not involve the fielders (hence “defense independent”). For example, DIPS focuses on home runs allowed, strikeout/walk ratios, and then fly ball, ground ball, and line drive percentages. The type of pitch is a factor in how the percentages change, but DIPS focuses on what the percentages really are, not how they were really formed.

There isn’t a formula for DIPS exactly, but sabermetrician Voros McCracken invented a formula for “Defense-Independent ERA” (dERA) for the statistic. It’s not really an equation, but rather a series of steps that you must do to calculate it. If you’re interested, google the steps. 

Here is an alternative formula made by Clay Dreslough called Defense-Independent Component ERA  (DICE):
 

Where HR is home runs, BB is walks, HBP is hit batters, K is strikeouts, and IP is innings pitched. That equation gives a number that is good at predicting a pitcher’s ERA the following year rather than the current year’s ERA.

Now with this statistic, it can get sort of complicated with pitchers. Like I said before, the type of pitch matters for DIPS, so a crazy pitch like a knuckleball or a screwball will be much different to face with a normal hitter. That’s why dERA is just not good with knuckleballers. It was tough to determine Tim Wakefield’s ERA (though Wakefield almost always had an ERA a little above 4). 

Don’t worry, though. Even with crazy pitchers like Wakefield, DIPS is still accepted in today’s baseball standards. Currently the lowest DIPS number belongs to Adam Wainwright of the St. Louis Cardinals, with a 1.99 DIPS. Anibal Sanchez of Detroit is second with a 2.12 DIPS. Only 15 pitchers have a DIPS of under 3.00, 11 of those 15 have ERA’s under 3, and 7 of them play for either the Tigers or the Cardinals. Maybe that’s why both of them are in first place in their division.


That’s about it for this week’s sabermetric special. Have any questions, comments, or concerns? Email me at statsbuddy42@gmail.com.

-Evan Boyd
“I like to feel that I understand little things about sports” – Bill James