It is no secret to veteran Orioles observers that Chris Tillman has struggled to date in the 2014 season. He currently is sporting an unseemly 4.91 ERA with a 6.78 K/9 (a full strike out lower than last year) and a 4.09 BB/9 (a full walk more than last year). So the question that comes to mind is why is he struggling so badly this year? Chris Tillman has never been a top of the rotation starter, but he is not this bad. Looking into some of the data, a few interesting changes to Tillman this year gives some insight to his struggles.
First and foremost, Tillman’s fast ball velocity has fallen to a career low. His average fastball velocity since his first start this season, in which he averaged 94 mph, has been between 89 to 91 mph. Velocity is not the end all be all of pitching, but faster pitches are harder for a hitter to make contact on, especially hard contact.
75 – 0.516
80 – 0.484
85 – 0.455
90 – 0.430
95 – 0.407
100 – 0.387
For a pitcher of Tillman’s style–a fly ball pitcher who pitches up in the zone–a fastball velocity that is even a little bit lower can be highly detrimental. For the past three months, his average fastball velocity has been lower than at any other point since 2012 (when he came to the majors full time).
Furthermore, the increased walk rate tells us Tillman has also lost control and command of his pitches. Furthermore, his swinging strike rate is a career low 7.1%. On top of that, the overall swing rate on his pitches is down, while the overall contact rate is up, especially contact rate on pitches in the zone. Tillman is not throwing quality balls that get swing and misses and is leaving too many pitches in the zone that are easy for hitters to barrel up. Nothing in these statistics show that Tillman is being unreasonably unlucky either, he has simply been bad.
However, determining why a pitcher has been bad is more difficult. Looking into what has been different with Tillman this year, a couple of aspects stand out. First, his horizontal release point has been very low his last couple of starts. While not a career low, he has dropped his arm down half a foot over the last three starts. Check out the graph below in which you can see how his arm slot has dropped precipitously recently.
I wanted to back this up with some video scouting and looking from the pictures below, one can see the shifted arm slot. In the first picture, Tillman on opening day is nearly straight up and down. In his most recent start against the Red Sox, in which he only gave up one run but yielded seven hits and three walks in six innings, his arm slot is significantly lower.
Also, Tillman has changed up his arsenal, chart below, some from years past as well. He is using his fastball and change more often than ever before. Also, he has backed up on his cutter usage, which could possibly be coming from the organization which has a publicized distaste for the cutter. These mechanical and arsenal shifts in usage could lead one to a bevy of different conclusions.
Looking at all this data, it’s hard to draw a concrete conclusion. I have personally stated on Twitter that I believe he is injured. To see his command disappear from him, his velocity drop, and his mechanics all change at once leads me to believe he is nursing an injury. In mid-May the issue of a groin injury came up. All of these aspects of Tillman’s game changing at once leads me to believe he is attempting to compensate for being hurt. However, the Orioles and Tillman continue to deny that he is injured. Therefore, it is possible that Tillman is simply altering his mechanics based upon his loss in fastball velocity to compensate. This theory is backed up by the change in arsenal, maybe Tillman and the pitching coaches are trying to reconstruct how he pitches on the fly to deal with the lower fastball velocity. Either conclusion is plausible, but I would not be shocked to see Miguel Gonzalez return and Chris Tillman find his way to the 15-day disabled list.