Trevor Cahill: Old, Yet Somehow New

You know the tale. The Oakland A’s acquire a young, talented player, develop him into a quality major leaguer, then trade him for more younger and talented players. Most of you reading this remember Trevor Cahill, but others may only know the name from whispers of a trade that brought key pieces of the team’s last postseason run, Jarrod Parker and Ryan Cook to Oakland.

Cahill was dependable, if not good during his time in Oakland with seasons of 32, 30, and 34 starts and no less than 178.2 IP in any of them. He had one truly great year as far as on-field results are concerned. A season in which he defied his peripheral numbers and posted a 2.97 ERA in just under 200 IP. He continued to be a solid, dependable innings eater in the two years with Arizona that followed, including his best year by fWAR’s standards. Still, Cahill was a pitch-to-contact, ground ball-oriented starter who walked far too many hitters than is ideal and post middling strikeout rates.

In 2014, and his final season with Arizona, Cahill experienced a subtle velocity bump that wasn’t even a full MPH over his previous season and it was exactly the same as his 2.98 ERA 2010 season. He also starting throwing his curveball a little more. Nothing extreme, just a few percent more than in previous seasons. He still threw his sinking fastball most often, with his changeup and curveball as the next most frequent offerings. He all but cut out his slider, which appears to be an anomaly. The results were his best strikeout rate ever, worst walk rate ever, and a FIP and xFIP both under 4.00. He was good and somehow also really bad as he posted a 5.61 ERA in 110 IP.

Cahill was traded to Atlanta and released not even three months later. He spent the next season and a half with the Chicago Cubs where he mostly appeared as a reliever. He was pretty good and it appeared that his career might be resurrected like many other failed starters before him thanks to shorter outings and elevated velocity. His velocity did increase to a career high 93+ MPH during his time with Chicago, as did his curveball usage to the point where he threw it 19% of the time in 2016.

The Padres grabbed him off the scrap heap late in the winter of 2017 and put him in their rotation. That’s when necessity and the Padres saved Trevor Cahill’s career.

Through 11 starts with San Diego Cahill was throwing the baseball better than he ever had before. The velocity gain from his bullpen days with Chicago stuck around and he threw his curveball more often than he ever had previously - a whopping 23.5%. He decreased his fastball usage and became a starter with a true 4-pitch repertoire. You’ll notice these changes have come with an increased swinging-strike rate without sacrificing the ability to get ground balls.

Cahill missed time with back and shoulder injuries in 2017, limiting him to less than 80 IP between San Diego and Kansas City. He was flat out awful in Kansas City, however that isn’t too surprising given the increased workload, velocity, and the fact that he’s human and bodies break down over time.

Early in 2017 Fangraphs’ Jeff Sullivan conceded that Trevor Cahill was good all of a sudden. It’s now a year old, but go read it. Overall his point was that Cahill was succeeding by inducing more whiffs on pitches out of the zone than most pitchers and by stealing called strikes more often than most pitches. Also, Sullivan noted the increased curveball usage. Newfound deception and movement from a seemingly reborn pitcher are what made him a sneaky good target at the trade deadline, even if it didn’t work out so well for Kansas City.

Flash forward to April 17th, 2017 for Cahill’s first start with the A’s in 7 years. One thing stood out to me in particular that I hadn’t really appreciated about Cahill in the past: his pitches move like crazy. Cahill’s fastball darted to the ground like a magnet had its way with it and his curveball looked sharp. Perhaps he saved the best stuff for his Oakland grand re-opening, or perhaps it was just because the Chicago White Sox are not a good baseball club. Whatever the case Cahill looked, even if only for one night, like the ace of this Oakland staff.

His fastball velocity topped out at 93.7 MPH, but sat at 91.6 MPH and he threw his curveball a new career-high 27.2% of the leading to 16% whiffs (15.2% between all pitches).

Nine years after making his major league debut an older Trevor Cahill revealed himself to be a new Trevor Cahill. He’s inducing more swinging strikes than ever and still getting ground balls at high rate - both qualities many great pitchers posses.

It was one start on an overall electric night in Oakland, so I know I’m getting ahead of myself. But so far in this young season not much of what Oakland pitchers have done has been good. Sean Manaea’s starts and Daniel Mengden Monday against these very same White Sox have been about the only bright spots on the mond for the A’s. I’m excited to see what Cahill can bring to the staff because the offense is doing its job - now it’s the rotation’s turn.