Profiling Masterson

After a handful of switches between the rotation and the bullpen over the past three years, Indians pitcher Justin Masterson is primed for his first full season as a starting pitcher. While Indians GM Chris Antonetti claims that the team has always viewed him as a starter, Masterson has seen his role change many times since his debut with the Red Sox in 2008. Here is a timeline:

April 24th, 2008: Masterson is called up from Double-A Portland to make his major league debut in place of the ill Daisuke Matsuzaka. Masterson is returned to Portland after the game.

May 19th, 2008: The Sox recall Masterson to fill in for the injured Clay Buchholz, this time sending him to Triple-A after his start.

June 3rd, 2008: Once again, Masterson is recalled to make a start. He replaces David Ortiz, who had suffered a wrist injury the day before, on the roster.

July 7th, 2008: The Red Sox option Masterson to Triple-A Pawtucket once again, and announce that with Buchholz returning from the DL, Masterson will be converted into a reliever.

July 21st, 2008: Masterson is recalled after three relief appearances at Pawtucket and pitches his first big league game out of the bullpen on the 23rd. He would remain in the Sox bullpen for the rest of the year and throughout the playoffs.

March 28th, 2009: The Red Sox announce that Masterson will make the 2009 squad as a reliever.

April 20th, 2009: Masterson is reinserted into the Sox rotation after Matsuzaka is placed on the 15-day disabled list.

May 22nd, 2009: Matsuzaka returns from the DL, and Masterson is sent back to the bullpen.

July 30th, 2009: The Red Sox trade Masterson to the Indians as part of the Victor Martinez deal. Masterson would make his Indians debut as a reliever two days later.

August 8th, 2009: Masterson joins the Indians rotation sooner than the team had anticipated, after throwing 46 pitches in three shutout innings the previous week.

March 5th, 2010: Indians manager Manny Acta says that Masterson will be the team’s third starter, slotting behind Jake Westbrook and Fausto Carmona.

September 12, 2010: The Indians send Masterson to the bullpen in order to limit his workload. He returned to the rotation again on the 18th to make a spot-start for the injured Mitch Talbot.

Yes, Masterson’s first three big league seasons have definitely been packed with plenty of action. According to Cleveland manager Manny Acta, Masterson is slotted as the Indians’ second starter in 2011 behind Fausto Carmona and, for the first time in his career, will not have any innings restrictions.

How he goes about it

You could say that the Jamaican-born, American-raised Masterson is something of a unique pitcher. The first thing to know about him is that he accummulates groundballs at a very high rate. Since 2008, his groundball rate has been .579, which is good for fifth in the majors behind Tim Hudson, Derek Lowe, Fausto Carmona, and Aaron Cook.

A Hardball Times Update
Goodbye for now.

Unlike many other groundball pitchers, though, Masterson is able to record strikeouts at a solid clip—he has .188 strikeouts per plate appearance over the past three seasons (.180 is league average for the time period).

Walks have been a problem for Masterson, and his career walk rate of 11 percent is 11th-highest in the majors since 2008. In spite of his control issues, the groundball and strikeout tendencies have kept Masterson at a Field-Independent Pitching (FIP) of around 4.00 for his career.

Masterson comes from a low arm-angle and throws four different pitches: a sinking fastball, four-seam fastball, slider and occasional changeup that he reserves for left-handed batters.

The chart below shows the aggregated spin deflection in inches, over the past three years, for his four pitches. It is from the catcher’s perspective, and “zero” represents a theoretical spinless pitch. Note that due to calibration issues at Fenway Park and Progressive Field, I’m only using data from road games for this graph.



Since 2008, Masterson has thrown the sinker more than any other pitch. Against righties, he’s thrown one 47% of the time, and against lefties, 37% of the time. Masterson’s sinker is the prototypical groundball pitch, tailing about nine inches in on a right-handed batter with one inch of topspin, which is impressive for a pitch that can get into the mid 90s.

The sinker has a combination of an above-average whiff rate (19 percent) and a stellar groundball rate (70.2 percent) since 2008, but is hurt by its lack of strike-zone frequency (over 55 percent have missed the zone, a high number for a fastball). Here is a picture of Masterson’s sinker grip.


Against right-handed batters, the four-seamer makes up only a quarter of Masterson’s arsenal, but that number is up to 39 percent against lefties (so he’s actually thrown a few more four-seamers than sinkers to lefties in his career). The four-seamer tails about two inches less and gets five more inches of “rise,” which is still as much movement as many two-seamers.

However, what’s interesting is that the extra movement, combined with its plate location, may actually be inhibiting the pitch’s effectiveness. As the graph below shows, Masterson can go “up the ladder” with the four-seamer while keeping his sinker lower in the zone:


Masterson only gets a whiff on 14 percent of swings on the fastball, which is solid, but unspectacular. I would theorize that due to the fact that it a) is up in the zone frequently and b) has a few inches less “rise” than the typical four-seamer, hitters are able to catch up to it more easily. It also had produced a solid, but unspectacular, groundball rate of 45 percent. Here is a picture of Masterson’s four-seam grip.


The slider might best be described as Masterson’s out pitch; he is comfortable using it to put hitters away, as he’s gone to it 32 percent of the time with two strikes against both lefties and righties. Overall, righties have seen it 27 percent of the time, and lefties 20 percent.

Each of the past three years, batters have missed on a bit over 35 percent of their swings against it, so it is certainly a good option to finish off hitters. It can pick up some groundballs (45 percent since 2008, but 52 percent last year), too, and is thrown for a strike enough to make it a well above-average pitch. You can see the grip for Masterson’s slider here.


The changeup is Masterson’s fourth pitch, and is usually only thrown when a lefty is batting (119 of his 128 changeups over the past three years have been against lefties). Percentage-wise, it’s 0.3 percent against righties and 3.5 percent against lefties.

I won’t spend too much time on the changeup because, so far, it hasn’t been very important to his arsenal. It moves pretty much like his sinker and is usually in the low 80s—be mindful that in some games it’s very difficult to distinguish between the changeup and slow fastballs, but I feel reasonably confident in the distinction I made.

It hasn’t gotten very good results so far and has been thrown for a ball over 45 percent of the time (Masterson’s other three pitches are in the mid-high 30% range), but, of course, be aware of the small sample size. You can see Masterson’s changeup grip here.

Mixing speeds

One of the most interesting things about Masterson’s game is his velocity. I remember as a rookie in 2008, he’d be around 90 mph, then all of a sudden he’d bump it up to 96 mph in a strikeout situation. After going through the data, I did see something interesting with Masterson’s velocity in strikeout counts.

Before we look at the velocity, it’s important to note how Masterson’s pitch selection changes based on the count. The following chart shows Masterson’s pitch frequencies in each count:


Particularly against lefties, Masterson is very comfortable going to his four-seamer with two strikes. With that in mind, take a look at his average velocity (road games only) in each count (no changeups in this graph due to sample size issues):


He’ll throw his pitches at least two miles an hour harder on average in pitchers’ counts than in hitters’ counts, which is a pretty significant difference. Now combine this with his two-mph gap between his sinker and four-seamer and his propensity to throw four-seamers with two strikes. He’s an entirely different pitcher when he’s going for a strikeout!

As a (more or less) random example, take this at-bat against Ramon Castro from his September 30, 2009, complete game against the White Sox:

1. Called strike; FF, 94.0
2. Swinging strike; SI, 90.1
3. Foul; SI, 93.8
4. Swinging strike; FF, 96.8

Looking ahead

What should the Indians see from Masterson as he enters his age-26 season? First of all, it would be wise to expect an ERA decrease, as he has been hurt by a .320 BABIP over the past two seasons; over that time period, Masterson’s ERA has been 4.63 while both his FIP and xFIP have been around 4.00.

The walks are concerning, but I’m sure the Indians would be thrilled if he could finally produce a 4.00 ERA over a full season. Masterson won’t be the only groundball specialist in the Indians’ rotation, as fellow starters Fausto Carmona, Mitch Talbot, and Carlos Carrasco have all had above-average groundball rates.

However, both Carmona and Talbot can’t get strikeouts and don’t have good enough control to make up for it (the jury’s still out on Carrasco), so it might be fair to say that Masterson has the best skill set in the rotation.

The future for Masterson is definitely bright, and if he can cut down on the hits and walks, the Indians may have themselves a legitimate ace.

References & Resources
PITCHf/x data are from MLB Advanced Media and are used here courtesy of Joe Lefokowitz’s tool. Pitch classifications are the author’s. Other stats are from Fangraphs and Baseball Prospectus.

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Mike Fast
12 years ago

Good article.  I need to sit down and read it again more carefully to digest it.

I really like the idea of plotting the velocity versus count.

12 years ago

This is probably the single best analysis I’ve read on a pitcher. Great work, I really hope that Masterson figures it all out soon.

Mat Kovach
12 years ago

Masterson’s biggest issue is against right-handed batters. The Indians are trying to get him to throw his change-up more to lefties.

So in addition to his walks, he needs to work on lefties or you’ll probably seen him moving to the bullpen.

12 years ago

The defense behind him isn’t doing him any favors. Is there any indication that he does much worse than normal for a pitcher from the stretch?

Lucas Apostoleris
12 years ago

Thanks for the kind comments, guys.

Mat: I was thinking about writing something about Masterson’s platoon split, but it didn’t wind up going into the article. 

Jacob: I don’t have the numbers on me, but it’s not too hard to dig up runners on base/bases empty splits.  I’m pretty sure Fangraphs has them.

12 years ago

@Mat Masterson’s biggest issue is against Left Handed Batters, where he is hoping to use his change up to be effective.

A very intersting comparison to Justin Masterson 2010 is to compare him to Edwin Jackson with the Rays in 2007.  You’ll find a similar trend in numbers and a similar disturbing “splits”.

Mat Kovach
12 years ago

@MrNegative1 Thanks for the tip.

Lucas Apostoleris
12 years ago

Thank you, MGL!  I was a bit reluctant to put the velocity vs. count numbers here since I haven’t really done a study on it league-wide … so that’s definitely a topic I’m going to dive into deeper.

Matthew Bultitude
12 years ago

Great article, except that the omission of the platoon discussion is glaring.  Masterson’s severe struggles against lefties overshadow his excellence against righties.

12 years ago

Right, at some point if a pitcher’s splits (estimated true splits, that is, and not just his observed splits) are so large, even if he is a decent or good starter, he may be more valuable as a reliever where you can leverage his much greater skill at getting same-side batters out.

12 years ago

Good stuff Lucas!  Really good.  I too especially liked the velocity versus count chart. I would like to see how that compares to all other pitchers, perhaps broken down by handedness and style (e.g., do sinker-ballers like Masterson have a similar profile, in terms of velocity v. count) as well.