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Masterson's Modified Mechanics

Masterson's Modified Mechanics
May 9, 2012
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Justin Masterson entered the 2012 season as the undisputed ace of the Indians’ rotation, posting a 3.21 ERA, 1.27 WHIP, and 2.43 K/BB ratio over 216 innings last year.  Masterson’s breakout campaign followed a couple of rough seasons where Cleveland gave him room to grow as a starter.  By learning to control his filthy arsenal, Masterson was able to significantly lower his BB/9, devastate right handed batters, and limit RBI opportunities for lefties (.746 OPS against in 2011, a career low).   

Since an impressive opening day win where he mowed down 10 Blue Jays and allowed just three base runners over eight innings, Masterson’s command has been suspect.  After an April 27th start against Anaheim that saw him go eight innings, but walk five and throw only 55% strikes, Tribe beat writer Jordan Bastian published this exchange:

Following the game, Indians manager Manny Acta noted that Masterson had slid more to the third-base side of the pitching rubber at the start of his delivery. While true, the pitcher said there is more to it than that.

"More or less, it's arm slot," Masterson explained. "It's kind of getting through the ball and not getting underneath it. That's pretty much what happened. Now, the movement on the rubber, in essence, is where we had been before. I kind of creeped over a little bit, so we scooted back over. In a sense, that would give you more room for error."

I’m always curious when players talk mechanics regarding their performance on the field and there are two points Masterson raises that I’d like to focus on today.  One is Masterson’s arm slot; we’ll return to that in a moment.  The other is his starting position on the pitching rubber. 

Acta stated that Masterson began the season with his windup closer to the 3B side of the rubber, with Masterson confirming that he had “creeped over” and recently moved back to his usual position.  I hadn’t noticed the change in position before, but sure enough, it’s clearly visible in the two screen shots from below.

3B Side     1B Side

After reviewing his first six 2012 games, I noticed that Masterson’s heel was located roughly half a foot closer to third base during his first three starts.  Those initial starts featured a heel position identical to the one in the left-hand image.  However, after a terrible start in Seattle where he surrendered 8 runs over 3.2 IP, Masterson abandoned the shift toward 3B and moved back to the far end of the rubber closest to 1B. 

As far as I can tell, the extreme 1B side was Masterson’s preferred position on the mound for the entirety of his career-best 2011 season (I checked his first start from each month of 2011 and found the same position used each time).  Here is one more screen shot showing Masterson against Texas on June 3, 2011:

2011 1B Side

I’m encouraged by this adjustment and think Masterson’s struggles will fade before becoming a more worrisome trend.  Whether it was a realization that he did not have a good feel for his pitches throwing from the middle of the rubber, the implosion in Seattle, or a combination of the two, it didn’t take Masterson long to return to what worked so well for him last season.  The numbers would back up this assertion, showing no clear advantage for either mound position in 2012.

Results from the move back toward 1B have not been consistent, but I’m a lot more comfortable seeing Masterson work through his issues from a familiar reference point on the mound instead of experimenting during the regular season.  To me, the scenario seems part mechanical and part psychological.  Based on the way he described the adjustment as “[allowing] more room for error,” it sounded like Masterson lacked confidence in his mechanics at the start of the season and moved his delivery toward 3B to compensate for the anticipated difficulties.  Small adjustments like this are probably typical over the course of a season for pitchers and Masterson’s did not seem like anything more than a band-aid to try and push through his early outings. 

Using pitch f/x values from Texas Leaguers, we can see that Masterson predominately used his fastball and sinker in 2011 and found the strike zone over 60% of the time with both pitches.  He also got batters to swing at these offerings nearly 50% of the time, regardless of whether they were thrown for strikes.









In Play





































So far in 2012, Masterson has gone to his sinker the most, while using his fastball sparingly.  This sample may be somewhat misleading, since the pitch f/x system can sometimes confuse a fastball for a sinker if it has a lot of movement like Masterson’s.  Even if you just focus on the sinker though, he has thrown it for strikes 5% less and gotten batters to offer at it 6% less often.  However, the fact that batters are still swinging through the sinker at roughly the same rate as last season (around 7%) suggests that when Masterson has good command, his bread-and-butter pitch is still just as enticing to batters. 

This brings us back to Masterson’s comment about how his arm slot has been giving him some trouble in 2012.  We know that Masterson is still fully capable of getting batters to swing-and-miss at his pitches, but he’s had difficulty commanding these pitches consistently.  Masterson seems to indicate that an inconsistent arm slot is the problem, meaning he hasn’t been releasing the ball on the desired vertical and horizontal plane at the end of his throwing motion.

The two pitch f/x charts below (also courtesy of Texas Leaguers) show the release point of every sinker Masterson threw in 2011 (top chart) and 2012 (bottom chart).  I’m focusing on the sinker here because I feel it’s the most critical to Masterson’s pitching style and it’s simply easier for me to point out the trend I’m interested in by un-cluttering the chart a bit.

Each point on the chart represents a pitch thrown, with its release point measured by height above ground (y-axis, in feet) and distance from the center of home plate (point 0.0 on the x-axis).  The point of view is from the catcher’s perspective.

2011 Release Points

Since Masterson is 6’6”, it may seem odd for him to be releasing the ball around the 4.50’ mark.  This is due to his sidearm delivery and low three-quarter arm slot.  We can see that in 2011, Masterson released most of his sinker balls between 5.25’ and 4.25’ feet off the ground and between -2.50’ and -1.50’ from home plate.

2012 Release Points

In 2012, the vast majority of his sinkers have been released between 5.50’ and 4.50’ on the vertical axis and between -3.00’ and -1.75’ on the horizontal axis.  On average, Masterson has been releasing his sinker at higher points and aimed farther from the center of home plate.  A similar trend was found with his fastball release points (not pictured). 

Considering the difference between Masterson’s 2011 and 2012 horizontal release points, it at least makes sense for him to move laterally along the pitching rubber (toward 3B in this case) in an attempt to compensate for the altered release point and influence the path of the ball more to his liking.  Commenting further on how the different arm slots and subsequent shifts along the rubber have impacted Masterson’s mechanics is a bit beyond my current knowledge, but his performance on the mound thus far and the fact that he felt a change needed to be made in the first place obviously suggest they’ve played some role in how he throws.

If the current arm slot trend continues it would pose a noteworthy shift in Masterson’s delivery between seasons.  As I stated earlier, I think Masterson is probably just working through some early season kinks, but I believe the arm slot changes (which Masterson himself pointed out to the press) are definitely worth monitoring in the first half of the season, especially if he fails to bounce back as I’m predicting.

User Comments

May 9, 2012 - 12:29 PM EDT
Excellent breakdown of Masterson here and to show that sometimes what these guys do say to the media is in fact true. No doubt there is an arm slot issue he is working through and they have tinkered with him a little with setup to compensate. Also, this is yet another reason why Masterson is a better "pitcher" than Ubaldo Jimenez. Masterson is not only mentally strong, but he has an awareness and the aptitude where he knows what is wrong. Now it is a matter of fixing it, which is not always easy.
May 9, 2012 - 12:17 PM EDT
Nice writeup. At least he seems to know what's wrong, and it's a matter of correcting it. The arm slot issues likely account for the drop in velocity too. Maybe to be awesome, Masterson requires Belcher.
May 9, 2012 - 11:33 AM EDT
Great stuff Brian, this reminds me of Fausto post-2007. Guys just couldn't lay off the sinker in 2007 and then in 2008 the book was out on him. Hope that Masterson can keep working to get the fastball and slider in place to complement the sinker from here on out.

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