Leaderboard of the week: ERA vs. FIP

One of the popular concepts in the baseball stats community is to look at a pitcher’s strikeouts, walks and home runs as a means for estimating what his ERA should be. The resultant stat is known as Fielding Independent Pitching (FIP), and is scaled similarly to ERA. The stat can be found on FanGraphs.com.

The idea behind this is that most pitchers with a good combination of strikeouts, walks and few home runs allowed tends to have a good ERA. Rare is the pitcher who doesn’t. If a pitcher has a bad ERA, but a good FIP, his ERA may be due to something beyond what he controls most. This could be the defense behind him, the ballpark he’s in, bad luck, or any number of factors.

Statisticians will often project a pitcher with a bad ERA and good FIP to improve the following season. The poster child for this is Rays starter James Shields, whose FIP indicated that he was far better than his 5.18 ERA in 2010. He responded with a 2.82 ERA in 2011.

How does this apply to April of 2012?

The three pitchers who had the widest differential between their ERA and FIP in 2011 were Derek Lowe, Ricky Nolasco and Brandon Morrow. Each had an ERA of 4.50 or higher. Each had a FIP of 3.70 or lower. All three have been great in 2012.

Derek Lowe, Ricky Nolasco and

Brandon Morrow:

These three aren’t the only pitchers with significant ERA-FIP differences who are thriving in 2012.

Giants starter Madison Bumgarner finished last season with a 3.21 ERA and 2.67 FIP. He won on Sunday and is 4-1 with a 2.53 ERA through five starts.

Dodgers starter Chris Capuano had a 4.55 ERA last season and a 4.04 FIP. He won Sunday and is now 3-0 with a 2.73 ERA through five starts.