Explaining Kyle Farnsworth’s Elbow Injury


Kyle Farnsworth completely turned around his career in 2011. But at the end of the season, he went down with an elbow injury, and that same injury has kept him out thus far in 2012. That was unfortunate because he pitched so well. But there was something off. Farnsworth has faced a multiplicity of injuries over the course of his career. But from 2002 until the end of 2010, he missed not a single game because of elbow injuries and just 8 games from shoulder injuries. Was there a specific reason that his elbow flared up in 2011?

I was thinking about Farnsworth and realized that there was something different about his delivery in 2011 compared to when I remembered him during his time with the Yankees. Take a look at this.

(For a general explanation of the topic of Pitch F/X and specifically how to read this type of graph, please click here.)

I do suggest clicking the link above, but in a nutshell, the lines on the graph indicate the vertical and horizontal movement on pitches, in this case, Kyle Farnsworth’s fastball from 2007-2011. The key tells you which color line depicts which pitch is which. You kind of have to see the graph in three dimensions. Each line depicts the vertical and horizontal starting point of each pitch- where Farnsworth holds the ball just before he moves his arm back to deliver, and then there is a semi-circle that depicts Farnsworth moving his arm back and dealing the pitch. The rest of the line is how the pitch moves vertically and horizontally until it’s end point where it’s caught by the catcher. What we’re particularly looking at here is Farnsworth’s release point, where the lines start on the top. The movement on Farnsworth’s fastball from all five years looks close to identical. But there’s a big difference between Farnsworth’s release point from 2007-2010 and in 2011. But what does that actually mean?

Here are two videos, the first from Farnsworth’s time with the Kansas City Royals in 2010, and the second from last season with the Rays, both courtesy of MLB.com.

If you watch these videos a whole bunch of times, pausing it at every phase of Farnsworth’s motion and comparing, as I’m about to do, a bunch of things become clear. The first thing that stands out is that Farnsworth shifted his position on the mound, going from the left side of the rubber to close to down the middle. That doesn’t seem very major, but it could have been what led to manifold minor mechanical changes.

When Farnsworth began his delivery, he had a higher leg kick with higher hands, and his elbow was more straight in his delivery in 2011 (on the right) compared to being more downward in 2010. Here’s a look at that. (All these pictures are from screenshots of the MLB.com videos.)

Then as Farnsworth brought his arm back, he went down at a sharper angle in 2011, providing more deception, but putting a ton of stress on his elbow as he went up.

As you can see in the second picture, Farnsworth’s arm is farther away from his right shoulder in his 2011 delivery, once again adding deception, but forcing to throw more across his body.

And Farnsworth’s actual finish is a more over-the-top delivery than the delivery he had before 2011. And we know that overhand deliveries put more stress on pitchers’ arms.

Kyle Farnsworth has started just 5 major league games after starting 21 as a rookie in 1999. There are multiple reasons for that, but one of them is that he has always had a ton of effort in his delivery. But in short relief stints, Farnsworth was able to mostly survive with his delivery. But it reached a tipping point in 2011. He adding even more stress to his delivery, and that was enough. Try copying Farnsworth’s 2011 delivery, even in slow motion. After I did it three or four times, my elbow started hurting.

Farnsworth mechanical changes helped him be as effective as he has ever been in 2011 as he posted a 2.18 ERA and saved 25 games for the first 20-save season of his career. But those same mechanical changes also caused his downfall. Luckily, Farnsworth’s 2011 success was not simply because of his new mechanics. He began using a sinker and cutter a lot more than he had previous, helping him force a groundball rate over 50% for the first time in his career. Hopefully Farnsworth can take just a little bit of the violence out of his delivery when he returns from the DL and stay healthy the remainder of 2012. Farnsworth definitely made huge progress as a major league reliever in 2011 and hopefully that progress can continue. But if his mechanics persist as they were in 2011, more DL stints because of elbow issues could be on the way.