Times they are a'Changin': Understanding Jarrod Parker's Struggles

Come gather 'round people, wherever you roam, and admit that ol' Parker's, ERA has grown - USA TODAY Sports

Editors' Note: This is another in a series of FanPosts from those AN members looking towards a weekly front page writing gig. This note will appear above every FanPost for this purpose. Community: please provide feedback and/or recs where you see appropriate.

Thanks! - cuppingmaster

A few weeks ago I discussed this season's struggles from Brett Anderson. Unfortunately, Brett isn't the only A's starter who has failed to live up to our lofty expectations this season. As of the time of this writing, Jarrod Parker, who many of us expected to be one of our top-line pitchers, stands with a unsightly 6.86 ERA.

Ouch. It hurts to even type that.

Even if we attempt to remove defense from the equation by using FIP, that doesn't help much. His FIP is 6.63. In this case, his FIP and his ERA seem to be pretty much in line. They are in agreement: Jarrod Parker just hasn't pitched very well this year. Not by any measure.

Unlike with Brett Anderson, it's a little more difficult to understand the root cause of Jarrod Parker's struggles. There are a lot of different things going on, but with the help of some more advanced statistics, we can try to pinpoint a few of Parker's key issues.

When you look at Parker's numbers this year compared to last year's, a few things should jump right of the page. One is that he's giving up a lot more walks- his BB% this year is 11.7%, whereas it was 8.4% last year. That's almost a 40% increase in BB%! Increased walks are not a good thing- more walks means more pitches, more runners on base, and being behind in more counts which increases the chance of leaving hittable pitches over the plate.

So why is Parker's walk rate so increased? Jarrod has certainly looked very wild here in the early going. Strangely, though, when you check his Zone%, which is the percentage of pitches that he throws inside the strike zone, he's actually throwing strikes at a higher percentage than last year (he's at 44.6% for this season, versus 42.2% last year). That doesn't make any sense...

We need to take a closer look at some of his pitches. Brooks Baseball, which is a truly incredible resource for evaluating pitcher performance, keeps track of many different statistics, including how much each individual pitch thrown by a pitcher moves. It sorts the data by pitch type, so you can take a look at the average fastball or the average changeup. What's especially cool is you can run splits from year to year- so we can take a look at how his pitches are moving this year versus last year, and how batters are responding to those pitches.

Something that immediately stands out is that Parker is getting fewer swings from his main pitches: his fastball and his changeup. What's especially striking (no pun intended) is that last year, batters swung at 55% of his changeups; this year, they're only swinging at 46%. In fact, batters are laying off of all of Parker's offerings. FanGraphs keeps track of a cool statistic called OSwing%, which is how often batters swing at pitchers out of the zone. Parker's numbers there are significantly down, which implies that his pitches aren't even close to the zone. He's not getting squeezed: he's just not fooling batters the same way he was last year.

Another significant difference between 2013 and 2012 is in Parker's ability to induce weak contact. One of the best types of contact for a pitcher is an infield fly ball, because an infield fly is almost always an out. As strange as it sounds, infield flies are actually a very hot topic in sabermetrics right now. In fact, FanGraphs just recently changed their formula for FIP to give infield flies the same value as strikeouts, because they so rarely go for a hit.

Last year, Parker had an IFFB% (infield-fly ball percentage) of 10.6%, which was good for #26 in the whole major leagues. This year, his IFFB% has dropped all the way to 0% (!!!). He has not allowed a single infield fly yet this season, whereas last year it was a huge part of his run prevention strategy. On the flip side, he's giving up more hard-hit balls than ever: his HR/FB% is a whopping 17%, more than doubling from his 6.8% rate last season. To put it more simply, his infield flies from last year, which were automatic outs, have been replaced with home runs, which are automatic runs. In other words: YIKES.

Basically, Parker's problems in 2013 are multiple: he's missing his spots, and he's not fooling anyone with his changeup. He gets behind in counts, which puts him in a position where he has to groove his pitches down the middle of the plate, and he's getting hit hard when he does throw strikes.

It cannot be stressed enough how important Parker's changeup is to his arsenal. Last year, Parker's changeup was a bona fide elite pitch. FanGraphs keeps track of pitch values, and last year Parker's changeup ranked 6th in the league, two spots above some dude named Felix Hernandez (for those keeping score at home, Tommy Milone was #4!). Its value on the year was +11.7, meaning his changeup prevented 11.7 runs above average over the course of the season, which is quite impressive.

This year? His changeup is already at -2.5, meaning he's giving up 2.5 more runs than average with his changeup.

Whew! That's a lot. The Cliffs Notes/tl;dr version:

* Parker is walking lots of people

* He's not getting people to swing at his changeup

* He's giving up more solid contact and significantly less weak contact

* His changeup, which was truly elite last year, has actually been a minus for him so far

The key for Parker going forward will be fixing his control, specifically of that changeup. His ability to prevent runs centers around that, and if he can get it back in form, I think we'll see a much improved Jarrod Parker going forward.