A Closer Look at the Red Sox’s New Starting Pitchers

In 2014 the average starting pitcher yielded a 44.6 GB% (ground ball percentage). Justin Masterson, Rick Porcello and Wade Miley, all of whom share the common bond of being new Boston Red Sox’ starting pitchers this year, are not the average starting pitcher in terms of inducing grounders.

Masterson’s 57.1 GB% over the past three seasons (2012-2014) is the third highest in the sport among qualifiers while Porcello’s 52.3 GB% during the same time period is the 14th highest. The last of MPM — a nickname I just created in the spur of the moment to represent the three offseason acquisitions using the beginning initial of their respective last name — which is of course Wade Miley, does not impress atop this leaderboard, as his 48.8 GB% in the above timeframe places him 32nd.

Using the arbitrary 2012-2014 time period for Miley, however, does not do him justice. In 2012, his first full season as a starting pitcher, he amassed a pedestrian (and what now looks more and more like an anomaly) 43.3 GB%, which has distorted his placement on this list. Now, in actuality that is not a “pedestrian” ground ball percentage; it, rather, is just a couple ticks below league-average (45.1 GB%) for the year. But for the guy the right-handed pitcher has become it was undoubtedly an aberration and for lack of a better term a “pedestrian” total.

Since that year he has transformed his batted ball profile and has immersed himself in the upper-echelon of ground ball pitchers, posting ground ball percentages north of 50% in each of the past two seasons. Changing that arbitrary period from 2012-2014 to 2013-2014 does do Wade justice. His 51.6 GB% in that span ranks seventh among all qualified starters.

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That was all a long and fancy way of telling you something that should have previously been obvious: Justin Masterson, Rick Porcello and Wade Miley are all fairly extreme ground ball pitchers. This is not earth shattering or original. Most of you probably were aware of this. If not, now you are. Exciting! I maybe reinforced some information. But why is this relevant? Why did the author (me) choose now to talk about this?

To answer those hypothetical questions, Matthew Murphy’s “Are Groundball Pitchers Overrated” piece on the Hardball Times exposed some pretty fascinating stuff about ground ball hurlers and it made me think about MPM because, well, they are all new to Boston and all are ground ball pitchers. If you do not wish to read the entire thing, which I hyperlinked above, I will just cut an excerpt out of it that should more or less sum the article up.

"“So, are ground balls good? Of course they are!However, this fact has led to a strong bias toward groundball pitchers (and against their flyball counterparts) in the baseball analytics community. Just because a ground ball in itself is a good outcome for a pitcher, it doesn’t necessarily mean that we should place a significant value on pitchers who are skilled at inducing grounders. In fact, pitchers who get a lot of ground balls often struggle in other facets of their game, particularly in managing fly ball contact. And while there are groundball pitchers who can avoid the long ball and maintain a solid pop-up rate (I’m looking at you, Felix), these pitchers are the exception rather than the rule.”"

The blockquoted text above comes from part of Murphy’s “Closing Thoughts” after he presented a bevy of evidence that ground ball pitchers are not as good as most perceive, especially  within the analytic community. Sure, ground balls are a desired outcome for pitchers because, as Murphy noted in his article, hitters in 2013 only managed to salvage an ugly .438 OPS off them. But of the prolific ground ball inducers he studied, Murphy found that, compared to low ground ball pitchers and average ground ball pitchers, ground ball pitchers tend to produce less infield flies, which are essentially always outs, post higher HR/FB%, and do not attain as good of a K%, which are also almost always automatic outs.

All said, as a consequence of these factors high ground ball guys tend to underperform their FIP and xFIP; meaning, their ERAs, which some may overlook because their peripherals — home runs, walks and strikeouts — were better than their ERA, have more substance than originally surmised. Typically, FIP and xFIP have been a better indicator of future performance for a pitcher than ERA, but that is not as much the case for ground ball pitchers.

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So, this got me wondering about Rick Porcello, Wade Miley and Justin Masterson. Usually, I favor peripherals when trying to predict how a guy will play going forward, yet with this fresh information in mind I thought it would behoove me to take a closer look at each guy to try and see how much, if at all, their peripherals are overselling (or underselling) these guys as pitchers.

For this “study” I will be looking at each guy’s HR/FB%, K%, and IFFB% — the above factors that are different for high ground ball pitchers — to try to see if I can get a better grasp of what to anticipate from each of them. What follows is not, by any means, an exact science. It is just a simple breakdown of each guy in terms of those stats and some thoughts that go along with the statistics.

Rick Porcello

• 2012-2014 (558 IP): 11.4 HR/FB%, 6.10 K/9, 10.7 IFFB%
• Same span: 4.08 ERA, 3.70 FIP, and 3.59 xFIP

Porcello, along with his ability to generate ground balls, does get his fair share of infield fly balls and does so at an above-average rate. This is a good skill to have, as mentioned, because infield fly balls are outs a vast majority of the time. The caveat that applies, however, is that infield fly balls (IFFB%) are strictly the percentage of fly balls that were flies in the infield; infield fly balls (IFFB%) are NOT the percentage of the total amount of batted balls. Considering the 26-year-old puts up a low FB% it is safe to assume that he did not get as many as infield flies as a lot of pitchers with a merely average fly ball percentage. A higher percentage, yes. More free outs, no.

Going from the positive to the negatives, we see Porcello does not strike a lot of guys out and he carries a higher than average HR/FB%. Both of these numbers are expected and are in-line with Murphy’s study of high ground ball pitchers.

I used to look at Porcello and see a guy who was just getting unlucky year after year, save 2014, and that his run prevention skills would inevitably catch up with his more polished peripherals. Given Murphy’s research, I am now a little more hesitant about the new number one in Boston — am I being presumptive? —  and see the gap between his ERA and FIP and xFIP as more of the byproduct of true talent, opposed to luck, than I used to.

Wade Miley

• 2012-2014 (598 2/3 IP): 10.8 HR/FB%, 7.13 K/9, 5.0 IFFB%
• Same span: 3.74 ERA, 3.71 FIP, and 3.67 xFIP

Strictly focusing on his batted ball profile, Miley was a completely different pitcher in his first full season (2012) than he has been over the past two seasons. We discussed the difference in ground ball percentages at the onset of this article, so I won’t bother talking about it again. But I will talk about how Miley’s 6.9 HR/FB% in 2012 has distorted the three-year HR/FB% presented above. In both ’13 (12.5 HR/FB%) and ’14 (13.9 HR/FB%) the right-hander has posted well above-average — or below? — HR/FB%. Unsurprisingly, the change came when he became a ground ball pitcher.

Miley’s strikeout per nine rate in that period is not as bad as Porcello but it is still below-average. His IFFB%, in contrast, is really below the average. Basically everything about Miley — his HR/FB%, K/9, and IFFB% — are trending in the less ideal direction; a direction Murphy’s data shows is typical of a ground ball hurler.

Unlike Porcello, Miley’s ERA has been oddly in check with his FIP and xFIP. The discrepancy between his ERA and FIP and xFIP is basically negligible at this juncture.

Justin Masterson

• 2012-2014 (528 IP): 11.9 HR/FB%, 8.01 K/9, 8.9 IFFB%
• Same span: 4.62 ERA, 3.94 FIP, and 3.83 xFIP

We have finally arrived at the final guy of MPM, Justin Masterson. His HR/FB% is the highest (worst) among the group but his strikeout rate is also the highest (best) among the new additions. Masterson’s IFFB% is below-average, as well.

As a result of a high HR/FB% and low IFFB% — something expected with any high ground ball pitcher — Masterson’s true talent probably lies somewhere closer to that poor ERA than his somewhat decent FIP.