Trevor Cahill: Consistently Inconsistent

In 2013 Trevor Cahill did not live up to expectations. He pitched only 146.2 innings, with an ERA of 3.99 and FIP of 4.26. He gave up a career-high 3.99 walks per nine innings. Cahill has struggled with walks throughout his career, but this is an alarmingly high rate. In 2012, Cahill gave 74 walks in 200 innings. Last year? 65 in only 146.2 innings, which brings us to our next issue: injuries. On June 19, the righty was hit in the hip with a line drive and came out of the game. Around the same time, a shoulder injury surfaced as well. He started twice after the hip injury, giving up 12 earned runs in 9.1 innings, before going on the disabled list. He was equally ineffective during the rest of June and ended the month with a 9.85 ERA, making it the worst month with most than one start in his career.

It’s easy to understand why he was bad in the two starts following his hip injury; he was pitching hurt. It’s harder to say why he was bad before the injury. Cahill infamously has not been able to control his sinker, which is by far his best pitch. With the especially high walk rate and his lowest strikeout rate since 2010, there seemed to be release point issues lurking.

Before we look at his release point, I want to make something clear: Trevor Cahill has yet to have a consistent release point. It’s so inconsistent that trying to find discrepancies might be a fruitless effort. Look at the different release points for just Cahill’s sinker in 2012:
all via texasleaguers.com and pitchf/x
Just for the sake of comparison, I pulled up the release point for ALL of C.C. Sabathia’s pitches in 2013.

The difference between Cahill’s highest and lowest release point was almost two feet. Trying to locate pitches consistently with that much variability on your release point seems difficult, to say the least. These struggles occurred in 2012, when Cahill was worth almost three wins.

While Cahill didn’t have a consistent release point, he was generally in the same region. In 2013, his release point indicates that something was different.

If you look carefully, you can see that his release point was a little further to the left from the perspective of the catcher. Maybe he dropped his arm angle, or maybe he just stood a little closer to third base. When the arm angle drops, there can be concerns about a pitcher losing deceptiveness on his pitches. In 2013, batters made contact with Cahill’s pitches both inside and outside of the strike zone at a higher rate. Batters were also better at laying off balls and swinging at strikes. Losing movement on his sinker could explain all of these issues. It’s possible that the different release points gave his pitches less movement, making them easier to hit.

It’s not all bad news though. If you remove the month of June from his yearly totals, his ERA jumps from 3.99 to 2.8. His walk rate also drops by 0.15 per nine. The Diamondbacks (and probably every other team) would love to have a starting pitcher with an ERA in that range. The problem is that it’s really hard to say what went wrong in June specifically.

When using statistics to look at a particular month, small sample sizes can make it difficult to draw meaningful conclusions. Out of the 24.2 innings he threw in June, 9.1 of them came after he was injured by the aforementioned line drive but before he went on the disabled list, and he pitched one inning before he got hurt on June 19. In those 10.1 innings he gave up 12 runs. He was just as bad in the few starts before the injury, highlighted by an outing with the following line: 3.2 IP, 9 H, 8 ER, 1 BB. In his following start he struck out 10 in 5.2 innings. Not many pitchers have the ability to be that dominant. The juxtaposition of those two starts tells you everything you need to know about Trevor Cahill.

It is unlikely that he will become a front-line starter unless he finds a consistent release point. Youth is on his side (Cahill turns 26 in March), but with over 900 innings of professional baseball under his belt, it’s hard to foresee a sudden improvement. There is no doubt that the hip injury hurt Cahill’s 2013 campaign. There was also that shoulder injury, which could have surfaced as a result of him compensating for a bad hip. Or it could have been an issue before the hip injury, potentially explaining his ineffectiveness in June. Cahill has the potential to be very good, but leaves something to be desired year after year. If he finds a comfortable release point and stays healthy, 2014 could be his year.