Brandon McCarthy was born on July 7, 1983 in Glendale, California, the third largest city in Los Angeles County. He later moved to Colorado Springs, Colorado around the age of ten where he would both graduate from high school and attend a year of community college. By that time in his life, he was a tall (six foot, five inches) and lanky teenager who could not throw hard at all--maybe into the mid-80's--but he could control his pitches. When he played his one season at Lamar Community College, he featured a four-seam fastball, a 12-6 curveball, and a change. None of them were plus offerings, but his control was what got him a ticket into the minor league circuit. In the 17th round of the 2002 MLB Draft, McCarthy was drafted by the Chicago White Sox.
Even though he was not much of a draft prospect, McCarthy quickly climbed the ladder. He spent three years in the minors, steadily putting up strikeout rates near ten per nine innings and walk rates near two per nine innings. He had capitalized on his control, and also worked to play up his velocity to a professional level. That definitely worked, as he made his Major League debut on May 22, 2005. He had a decent rookie campaign (runs allowed wise), but with poor peripherals. In 67 innings he pitched to a 90 ERA-, but a 112 FIP-. Allowing 1.7 HR/9 does not help that. McCarthy had similar struggles for the next few years. He only pitched in 84.2 innings in 2006 (1.0 RA9-WAR, 0.1 fWAR), and then he was traded to the Texas Rangers for John Danks, Jake Rasner, and Nick Masset. By that point, it appeared that his career was in jeopardy. Between injuries and relative mediocrity, McCarthy was bouncing between disabled list stints, the big leagues, and Triple-A. That's when he realized he needed to change.
In 2009, he decided to become a self-taught sabermetrician and player. Sabermetricians are traditionally people like me--someone who never played an inning of professional ball but are trying to make sense of it. The idea was that stats were supposed to stay with the stat-heads. Players were supposed to play with as little complication as possible to avoid confusion. McCarthy distorted that narrative and turned his career around. He developed his four-seamer into a two-seamer and pitched to the ground ball. He learned to try to block out the things he couldn't control (hits due to BABIP), and to worry about what he could control--walks, strikeouts, and home runs. When the Athletics signed him in 2011, he did just that. In 170.2 innings and 25 starts, McCarthy was the AL leader in FIP (2.86). This was partially because of his deflated HR/FB ratio in O.co, but also because he cut down on the walks immensely. By fWAR, his season was a success. He racked up 4.5 fWAR (3.2 RA9-WAR) and was one of the better pitchers in the league at that time. This transformation was documented in the famous ESPN The Magazine article, which you can read here.
Since then, his game has not changed much, but injuries have plagued him. He has not thrown more than 150 innings in his career and has not topped his 25 start season in 2011. At most, he threw 22 starts last season. In terms of FIP, he's been eerily consistent. In 2012, 2013, and 2014, he's pitched to FIP's of 3.76, 3.75, and 3.79, respectively. This season his ERA has skyrocketed to 5.01, but the Yankees are betting on a much-needed positive regression. He does let up some home runs, something that righties are wont to do in Yankee Stadium, but that should still be counteracted by the fact that he is a better pitcher than his runs allowed implies.
I think what we can gather from all of this information is that Brandon McCarthy is an incredibly smart pitcher. If this isn't 80-grade makeup, then I don't know what is. He took a build and profile that was not all too attractive at the draft and played it up so that he could get to the big leagues. And when his strategies did not work, he reinvented himself so that he could compete. He was open to anything to make that happen, and that just so happened to be analytics. It's made him a darling among sabermetricians as he's become a case study of a sabermetrics success story. Although his natural pitching tendencies do not match up ideally with his new home park, his pitching IQ is high enough that he will be able to adjust accordingly. Although he is just a rental, I am incredibly excited to see what Brandon McCarthy can do in pinstripes.