SABR-Toothed Triber: Mastering Masterson’s Splits

Note: The bulk of this piece was written before Justin Masterson’s start last night, so take most of the 2010 charts with multiple grains of salt, as they only include his first start of the season against the White Sox. In January, Manny Acta and Mark Shapiro announced that Justin Masterson would be given a shot in the starting rotation, marking the first time in Masterson’s major league career that he would be in an opening day rotation.  While much has been written about who would fill the #4 and #5 spots in the rotation, I’d like to take a look today at some of Masterson’s numbers, to see what we might be able to expect from the youngster in a starting role. Masterson started sparingly with Boston in 2008 and 2009, but after coming over to the Indians, he only pitched 3 innings in relief, working instead as a cog in Cleveland’s tattered ’09 rotation.  Here’s a brief look at how he’s done in his various roles since coming to the majors in 2008 (I’ll leave out his three scoreless innings of relief with the Indians):


As a reminder, FIP is an ERA estimator that attempts to remove defense and luck, so when you’re looking at FIP numbers, just think of ERA—the lower the better.  It should come as no surprise that Masterson has pitched more successfully as a reliever than a starter: most pitchers do, since they don’t have to face the lineup more than once and don’t have to worry about pacing themselves for multiple innings. But when you’ve got a young, big pitcher with good stuff, you’d like to make him a starter if possible.  After all, starters have far more influence on the outcome of a game than relievers, so you’d prefer to have your best pitchers in the rotation.  The only reasons to move a promising arm to the ‘pen are potential injury concerns or problems getting batters out from both sides of the plate.  Guess which one Masterson struggles with? Let’s look at some data: Above is a graph presenting Masterson’s batting average against for the past three seasons, split by the handedness of the opposing batter.  See anything that jumps out at you?  Right-handed hitters bat right around .200 off Masterson for his career, but lefties went from batting around .250 in 2008 to over .300 in 2009.  Some of that jump can be attributed to the switch from the bullpen to the rotation (all the averages went up in ’09 as he made his transition to starting), but it’s obvious that lefties just hit him better than righties, and considerably so.  But why? Well, most pitchers have a “platoon” split—meaning that they perform better against same-handed batters.  But Masterson’s splits look to be fairly pronounced.  For comparison’s sake, Aaron Laffey (LHP) has a 4.03 career FIP against left-handed batters and a 4.69 FIP against right-handers, a fairly typical platoon split.  Masterson (RHP)  has a 5.10 FIP against lefties and a 3.54 FIP against righties!  That’s nearly 3 times the size of Laffey’s split. Let’s look at some of Masterson’s peripherals to see what we can learn.  Here are his strikeout rates (K/9): Better against righties, and again, by a considerable margin.  He strikes out about one batter per inning when facing righties, but averages fewer than 7 Ks per 9 IP against lefties.  As far as strikeouts go, that’s roughly the difference between Josh Beckett and Carl Pavano.  Now here’s his walk rate (BB/9): The major league average is right around 3.5 walks per nine innings pitched.  Against righties, he’s better than average, but against lefties?  He’s as wild as 2009 Fausto Carmona.  Weird. One more graph.  This one presents his BABIP (batting average on balls in play): Typically, pitchers don’t see a huge variance in their BABIPs; they generally settle in the .290-.310 range.  But Masterson?  When righties put the ball in play against him, they’re batting around .250, while lefties had their batted balls drop in about 36% of the time last season!  Some of that difference might be attributable to luck, but it’s pretty clear that lefties are squaring the ball up against him, while righties are more likely to make weak contact, resulting in more outs.  To summarize, check out these splits for Masterson’s entire career:

vs L6.815.431.04.286.3305.10
vs R8.592.970.76.197.2463.54

Pretty one-sided.  Or one-handed.  Whatever.  Lefties kill him. To get to the bottom of the cause for these massive platoon splits, let’s look at Masterson’s pitch types.  Here’s a pitch chart from Masterson’s first start of the 2010 season, against the White Sox:

Think of this image as if you were the catcher.  The green dots are his four-seam fastballs; the blue are the two-seamers, and the red represent his sliders.  The chart doesn’t indicate pitch position but pitch movement.  What do we see?  Well, his two fastballs are basically the same pitch, with the four-seamer getting slightly more upward tailing movement.  Both tail horizontally to the catcher’s glove side.  Obviously, this movement tends to jam right handed batters, but lefties can just take that pitch the other way (or up the middle).  Furthermore, his two-seam fastball has some sink to it, which helps Masterson generate weak groundballs against righties.  Now look at his slider.  The movement is minimal, but tends to be downward and toward a left-handed batter. So imagine you are a left-handed batter standing in to face Masterson.  What do you do?  Well, I’d crowd the plate.  His slider doesn’t move in enough to jam you, and all you have to cover is the tailing movement on the outer half of the plate from his fastballs.  His fastball speed averages about 91 mph and his slider 83 mph, so he’s got some separation in speed, but not the 10 mph that generally make off-speed pitches “unhittable.”  Either way, 91 mph isn’t going to blow anyone away, so there’s some time to adjust. It’s certainly more complicated than this, and there are various explanations for Masterson’s huge platoon splits. The Indians have suggested that the key to his problems against lefties lies with his inability to develop a strong changeup.  The ideal changeup would drop down and away to a left-handed batter (putting it in the bottom left quadrant of the graph above), and would prevent opposing lefties from sitting on his fastball or slider, that “slides” right into the sweetspot of their swings. According to Manny Acta, “Masterson has worked very hard on his changeup.”  So hard, in fact, that against the White Sox, he threw exactly….ZERO CHANGEUPS. But Jon, you’re saying, he pitched great against the White Sox last week.  One run over five innings.  Five strikeouts.  Et cetera, Jon!  ET CETERA! I hear ya.  But, guess what.  The two (yes, only two) left handed batters Ozzie Guillen ran out against Masterson last week were Juan Pierre (.338 wOBA in 2009) and AJ Pierzynski (.326 wOBA in 2009).  In other words, the White Sox have no left-handers who can hit. Against the Rangers?  Well, as of 8:29 PM, Texas had run out three lefties against Masterson.  Here were their numbers:

Total75 0.714

Um.  Yikes.  And I haven’t yet seen a changeup. I’m gonna watch the rest of this massacre.  See you next week with some thoughts on what we can expect from Carlos Santana if/when he gets the call… -Jon Steiner

  • Sactoriuous

    I sure am glad I took those Graduate level statistics courses.

  • Tommy

    So do we know why he has struggled to develop a change up so much? Is it something that is just not going to happen? I’d have to think, with the right coaching he should be able to develop something at least passable.

    And how bout the possibility of a cutter? I know its a fairly similar pitch to the slider but i think it could help him jam lefties and keep them off the plate, making his away movement on the fastballs, and potentially a change up more effective. The cutter seems to be the popular pitch to keep opposite handed batters neutralized for a lot of guys around the league right now.

    And you didn’t give us your projection. What do you think is the end result for Masterson? Does he end up as a reliever? Is there anyone that has been successful as a starter for an extended period of time with splits as big as his?

  • Tommy


    Sorry that has nothing to do with this post, but the Tribe couldn’t have needed a big hit any more. Come on Perez lets throw strikes

  • Jon Steiner


    First, according to Pitch/fx data, Masterson did throw a change up last night. It was clocked at 89 mph. That just isn’t going to cut it.

    Tommy, I can’t speak to how Masterson’s been coached. I also don’t know how difficult it is for pitchers to develop new pitches once they’ve reached the majors. But I DO know that Dave Duncan has taught countless pitchers to throw a sinker, generally to great effect. Pitchers can learn new tricks, and we should remember that Masterson’s “only” 25 years old.

    I hear what you’re saying about the cutter, but a cutter would be below a changeup on my wish list. While pitch movement is a concern, I think that until Masterson can keep lefties off-balance with changes in velocity, he’s going to struggle.

    My prediction is that this will be a rough year for Masterson, but that we will ultimately keep him in the rotation. I would say it’s safe to assume that if he stayed with Boston, he’d have been a reliever; they can afford to have good relievers. All our good relievers need to be in the rotation because we have no great starters. I also think that we should probably give him time to develop (like, maybe a year) and to work on a changeup or cutter–it’s not like his difficulty with lefties will be the difference between contending and not.

    His upside as a starter is definitely there, if he can figure it out: he did end up striking out 9 guys last night. Not too shabby.

  • Tommy

    Thanks for the response… I think I’m on the same page with you, unfortunately I think he is going to struggle this year.

    How bout Huff though?? So glad this guy made the rotation. I think we have to let him develop too. Its hard not to think Cliff Lee when you see him pitch. The motion, arm angle and the way he attacks hitters is so similar to the ex-Indian.

    And on another note, I’d be willing to sacrifice an out every time through the lineup for the rest of the year if Redmond can keep getting his pitchers to throw like Carmona and Huff have so far. Small sample to be sure but just sayin.

  • JK

    Hey! How come nobody told me that the Tribe was on? I could have effectivly wasted atleast a quarter of my work day.

  • Jack

    Just look at the photo accompanying this.

    That release point does not bode well for fooling left-handed batters.

    “Let’s go ahead and take that FROM THE TOP, Justin…”