The Thing About Bobby Parnell Becoming a Starting Pitcher…

… is that he still is a one-pitch pitcher.

According to Fangraphs, in 2009, 79.4% of Bobby Parnell’s pitches have been fastballs.

The following is a list of all of the starting pitchers in MLB who have thrown at least 100 innings and have thrown more than 79.4% of their pitches as fastballs:

1. Aaron Cook – 85%

That’s it. Mike Pelfrey clocks in at #2, throwing fastballs 78% of the time.

As a reliever, the limitations in Parnell’s repertoire are less unique.  Here are some pretty solid Major League relievers with a Parnell-eque fastball frequency:

• Matt Thornton – 90%
• David Aardsma – 88%
• Ronald Belisario – 84%
• Grant Balfour - 81%
• Jonathan Papelbon – 80%

So clearly, a pitcher like Parnell can have success in the pen, but guys like him are a much less commonly seen starting games.  The explanation for this seems obvious – it should be hard to make it through an opposing lineup 3 or 4 times relying on one good pitch.  One good pitch can get you through a few batters, but probably not 7 or 8 innings.

Unfortunately, the Mets took Parnell out of the minor leagues last season before he had finished perfecting his secondary pitches while starting in AAA.  They turned him into a reliever at the Major League level, and now he’s now spent a fairly decent year in the Mets bullpen. He’s been productive, but the Mets are clearly going nowhere.  Now, he’s back in the rotation and seems set up to fail.

If they wanted to turn this guy into a dominant reliever/closer, they should leave him in the ‘pen.  If they wanted him to ultimately start in the big leagues, then he should have started this season in AAA working on his slider and change up.  Just another example of lousy, short-sighted management by Omar Minaya and the Mets.