The Secret to Jarrod Parker’s Success

Just a few days ago I wrote that you should drop Jarrod Parker. In case you’ve forgotten, I’ll refresh your memory:

Parker has been a revelation for Oakland. He’s been so good that it’s rather surprising he’s owned in just 42 percent of fantasy leagues. He also has a 2.41 ERA and 1.05 WHIP in three September starts, so it might be more surprising that I’m telling you to drop him. But the problem with Parker isn’t his performance, it’s his opponents.

Then Parker had to go and dominate the Yankees at Yankee Stadium to the tune of just one earned run, six hits, zero walks, and seven strikeouts over eight pristine frames. Despite pitching so well, I still maintain that I’d rather not start Parker in his outing at Texas, but now I would definitely start him in his final home start of the year against the Rangers.

I love writing about pitchers, so I thought I’d take a look at exactly why Parker has been so good and, by extension, if this is success we can expect as he enters year two of his career next spring.

Success on the mound boils down to three main factors: limiting walks, generating strikeouts, and inducing grounders. If a pitcher can do those three things at an above average level, they’re going to be an above average starting pitcher (unless their name is Ricky Nolasco). While his strikeout totals have dropped off over the last two months, Parker has shown marked improvement in his walk and ground ball rates. Unsurprisingly, success has followed.

Take a look at Parker’s BB%, K%, GB%, and FIP as he’s matured this season. (FIP was used instead of ERA because 30-inning monthly samples generate a lot of ERA volatility.)

Aside from an August swoon, Parker’s FIP dropped steadily in May, June, and July down to 3.27 this September. That decline coincided with a drastic rise in GB% to nearly 50 percent in June, July, and August and now over 50 percent in September. His BB% has dropped pretty much every single month and now rests at just 2.7 percent.

Parker has excelled using his change-up, a pitch which has averaged a 12.4-mph difference in velocity with his fastball. That’s the third-largest gap in pitch velocities in the majors this year of the 64 pitchers who’ve thrown a change-up at least 10 percent of the time. Not surprisingly, Parker’s change-up rates as the 15th-best in the league this season according to PitchFX (measured in runs above average per 100 thrown). Just nine months ago Athletics Nation wrote that Parker’s change-up “has improved a great deal, ranking plus at its best,” and my guess would be that this pitch will improve as the 21-year-old improves.

(To see just how much the fastball-change velocity gap impacts a pitcher who features both offerings as frequently as Parker does, check out this post on Francisco Liriano. It plots how his ERA has fluctuated with his fastball-change gap.)

Oakland has something special in Parker. Like I said in the opening I wouldn’t be starting him at Texas in my fantasy league, but I would certainly start him in his final home start. As for 2013 and beyond, Parker is someone to target in all fantasy leagues and is most likely a top-25 starting pitcher for the coming season.