More fun with DOM

In case you missed it earlier tonight, I wrote about the Braves' usage of DOM and where the team's pitchers stood in the grand scheme of things. As I thought about it and crunched all the numbers, I thought that DOM might favor relievers more than it did starters, after seeing the higher numbers posted by the team's bullpen in 2011. So I decided to take it upon myself to do a little more research into the topic.

Here are the top ten DOM numbers for relievers in baseball in 2011.

Koji Uehara	1.809
Kenley Jansen	1.714
Craig Kimbrel	1.588
Jonathan Papelbon	1.450
Tyler Clippard	1.405
Rafael Betancourt	1.352
David Robertson	1.333
Greg Holland	1.321
Sergio Santos	1.314
Antonio Bastardo	1.296

 
The highest FIP of those ten players belongs to Clippard, at 3.17. Of the top ten relievers in baseball in FIP, five are on that list, including all of the top four.

Now, let's look at the top ten DOM numbers for starters in baseball in 2011, qualified starters only.

Clayton Kershaw	1.088
Justin Verlander	1.082
Cliff Lee	0.996
Zack Greinke	0.976
Cole Hamels	0.923
Michael Pineda	0.920
Roy Halladay	0.905
Josh Beckett	0.884
Brandon Morrow	0.879
James Shields	0.865

Of that list, the highest FIP is Morrow at 3.64. Of the top ten starters in baseball in FIP, five are once again present, including the top three. 

What does this little exercise prove? Relievers will generally have a higher DOM than starters. In fact, there are 16 relievers who have DOM values higher than the best starter.

The correlation between FIP and DOM isn't strong, but there is a slight one there. The average reliever DOM (among qualified candidates) was .778, and out of all 34 relievers with a FIP lower than 3.00, six had a DOM above league average, only one had a groundball rate that wasn't more than 12% above the league average of 44%: Darren Oliver.

When it comes to starters, the average DOM (among qualified candidates) was just 0.635. Of the 45 players with a DOM higher than that mark, there were seven with a FIP above 4.00. Of those seven, only Ricky Romero and Wandy Rodriguez (by 1%) had a groundball rate HIGHER than the league average of 44%.

Now, what does THIS show us? DOM is a better indicator of player success than it is for relievers than for pitchers...unless we're talking about groundball relievers, then there is more of a chance for variability. For starters, an above average DOM isn't a perfect indicator of success, but it's not completely meaningless either. Approximately 83-85% of pitchers with an above average DOM will have a solid FIP. 

It's not an exact correlation, but it's pretty accurate. If you figure in all starters and relievers as opposed to qualified ones, the bar gets lowered dramatically. For example, looking at all relievers as opposed to qualified ones pushes the average down to 0.669, which would put 83 of the 134 qualified relievers above average. For starters, the bar falls to .570, which puts 55 of 90 qualified starters over the average guideline.