Pitches Per Plate Appearance: Reliever Edition

Now we saw with Starting Pitchers that their was a slight positive correlation between pitches thrown per plate appearance and pitching efficiency. Here, I do the same survey with relievers. I used the NL West, with the requirements that the pitcher had no starts, at least 10 relief appearances, and tried to only use pitchers who had at least 2 years of MLB experience. Click on the images to enlarge.

12 of the relievers had a negative correlation for the more pitches per plate appearance, while 10 had a positive reaction. 17 had no real correlation. This means, as we saw with starting pitchers, it is basically worthless to argue that a change in Pitch/PA had any kind of effect on a change in effectiveness in a pitcher. However, like starting pitchers, pitchers who throw more pitches on average are more efficient. Pitchers that had at least 4 pitches per plate appearance had an average PE of -2.44. Relievers that averaged less than 3.7 Pit/PA had an average PE of .88. This probably is best explained by the fact that pitching efficiency relies heavily on strikeouts and to strike people out, you usually have to throw more pitches. However, it does seem that all the elite relievers are heavy strikeout pitchers. So while Pit/PA can't be an explanation for why a pitcher is good or bad one year, it seems that the larger Pit/PA a pitcher (both for starters and relievers)
has the better he is (at least on average).

The Transformation of Matt Lindstrom

Matt Lindstrom, currently a reliever for the Colorado Rockies, had a profoundly mediocre year for the Houston Astros last year. His ERA was 4.39 and his WAR was .3, which gave him a WASP of 5416.7. It was no surprise at all that the Astros didn't bring him back. For the Rockies this year, he has been much better, a 3.06 ERA with a 1.2 WAR. Even after the bad year of last year, the Rockies still paid Lindstrom more than he made in 2010. In fact, he is making nearly twice as much. However, his WASP is still a decent 2750. What are the reasons for this change? Well, there could be several. For one, he appears to be more healthy this year, he spent some time on the DL last year for the Astros, and didn't appear to be the same pitcher down the stretch and was yanked from the closer position. Statistically, Lindstrom was more of a strikeout pitcher last year, with 7.26 K's per 9 innings (5.94 K's per innings this year). He has walked less people though (2.52bb per 9 innings this year, and 3.38bb per 9 innings last year), and when people put the ball in play, they have done a lot less damage this year (.358 Batting Average on Balls in Play last year and a BABIP of .283 this year). The Astros sure could have used this year's Matt Lindstrom last year or this year.