Kelly O’Connor/

I last saw Jake Peavy pitch, live and in person, nearly seven years ago.  Paradoxically, I remember it vividly, yet vaguely. More accurately, there are elements of the game I remember with clarity, but on the whole, it’s mostly a haze in my mind. I remember it being incredibly hot; I could feel the sun singeing the nape of my neck. I remember it being the last game I would see in San Diego before I left for college. I remember seeing a young Tim Lincecum exhibit flashes of the brilliance that had yet to come. And I remember Jake Peavy, carving up an admittedly anemic Giants lineup (the highest OBP in the lineup was Dave Roberts’ .330 mark), for 7 1/3 innings. The game went by extraordinarily quickly, wrapping up in just under two and a half hours. I credit the game’s brisk pace to Peavy’s unrelenting attack against Giants hitters. He had ten strikeouts, eight of the swinging variety. Somewhat surprisingly, those eight swinging
strikeouts made up the bulk of all the swinging strikes he induced throughout the game (15 whiffs or 14.4% of all pitches thrown). Nine of those 15 whiffs came via the cutter.  It was kind of an effectively wild pitch, as you can see from the strikezone plot below.

Courtesy of


He liked to run it up and away from lefties, but apart from that it was kind of
unpredictable. Peavy’s cutter had some nice vertical movement, but part of what made it effective was the 8 MPH velocity differential between his fastball and his cutter. Peavy worked quickly and efficiently, and he was difficult to time. He also used the entire strike zone, so it was often near impossible to anticipate the location of any given pitch.  Obviously, this is a near impossible task for any hitter, but with some pitchers, a hitter can learn their patterns and adjust. Peavy, it seemed, would just let his pitches fly, and because hitters had such difficulty timing his pitches, they would often feel compelled to swing and just hope for the best. Not only did Peavy have great stuff, but he also had the swagger to match it. He had a cheek full of dip, and he’d scream, yell, and curse at himself on the mound. I can only imagine how terrifying it must have been to face Jake Peavy in his prime.

2007 was easily the pinnacle of Jake Peavy’s career. He won the pitching Triple Crown, and he won the Cy Young Award, unanimously. 2008 saw Peavy decline a bit, but he was still among the elite. He lost a few miles per hour on his fastball (which may have been a harbinger of things to come), his strikeout rate dropped slightly, his walk rate ticked up, and his FIP jumped by nearly .8 points, from 2.84 to 3.60. He wasn’t quite in free fall, though, because he made some mild adjustments that kept him in the upper echelon of MLB pitchers. He slightly increased his usage of breaking balls. He mixed in a
curveball and a slider, while reducing his reliance on his sinker and his cutter. This led to a slightly expanded arsenal of offerings; thusly, it had become increasingly difficult for hitters to predict the pitch type. Peavy must have recognized this approach was working for him because the following season (2009) he nearly tripled his curveball usage. He maintained a balanced approach, too. While his fastball was obviously his primary pitch (like many MLB starters), there was even distribution among his secondary offerings, which, again, made it difficult for a hitter to identify a pattern and develop a game plan.  He also markedly improved his control; he was throwing strikes in the zone almost 5% more than in recent years. Consequently, his strikeout rate shot up 3%, and his FIP fell by .6 points, settling at 2.99 by season’s end. 2009, of course, was the year the pitiful, miserly Padres traded Jake Peavy to the Chicago White Sox for a package of players that went on to accumulate 3.4 career fWAR. Only one of whom still plays in the majors (Aaron Poreda, a reliever for the Rangers. I imagine he’s only in the majors because the Rangers have endured nearly unprecedented bad luck with injuries). Peavy, conversely, went on to accumulate 11 fWAR in parts of 5 seasons with the White Sox. Realistically, it was about 3.5 seasons of actual playing time with the White Sox because of his long stretches on the DL and being traded mid-season to the White Sox in 2009 and from the White Sox (to the Red Sox) in the middle of 2013, but I digress…

Photo by Leon
Halip/Getty Images via Chicago CBS Local News


In 2010, Peavy’s whiff percentage plummeted. His breaking balls were a little flatter, and he lost about one mile per hour of velocity on his fastball, which can have huge effects. He also began giving up home runs on ten percent of fly balls; his highest rate since his sophomore season in the big leagues in 2003. He was hurting. On July 7th, 2010, he went on the 60-day DL, and 7 days later, on July 14th, he underwent surgery to repair a detached latissimus dorsi, a muscle crucial to the act of throwing a baseball.  He was out for the remainder of the season, missing 80 games.

While a latissimus dorsi strain is not a very common injury among pitchers (much less position players), it isn’t exactly rare either. As orthopaedic surgeon Dr. David Geier
writes on his blog:

Interestingly, several major league pitchers have reportedly suffered injuries of the latissimus dorsi, including Kerry Wood, Brad Penny, and Jake Peavy.  While most of them were partial tears of the tendon and thus could be treated with rest and physical therapy, Peavy needed surgery to reattach the tendon when it pulled completely off the bone.

Firebrand’s own, Evan Brunell, wrote in 2011 about Peavy’s surgery: “torn lats are not only the most common career-ending injury for pitchers, but the surgery used to mend the shoulder is rife with issues.” Evan went on to describe the somewhat unique surgery that Peavy underwent to repair his detached latissimus dorsi:

‘A superior labral or SLAP tear often involves the biceps tendon which
attaches in the same area,’ [Dr. Anthony] Romeo [White Sox co-team physician] said.  ‘If the capsule injury and the biceps attachment and the fibrous tissue area around it are not fixed or repaired along with the labral tear, the pitchers will still have pain.’

So, Dr. Romeo repaired, for the first time ever on a pitcher, not just the detached
latissimus dorsi tendon, but also the “fibrous tissue area” around the biceps, in an
attempt to prevent further degradation of the muscle, which could potentially limit
Peavy’s effectiveness in the future.

In 2011, Peavy began the season on the DL, while recovering from right shoulder
rotator cuff tendonitis. Peavy was understandably discouraged as he had already
recovered from the latissimus dorsi surgery and was now dealing with myriad injuries including the aforementioned rotator cuff tendonitis and a mild right groin strain that landed him on the DL in June, less than a month after coming off the DL for the shoulder inflammation. In spite of the seemingly never-ending litany of ailments, Peavy persevered and had a surprisingly solid season. His ERA at season’s end (4.92) belies just how good he was in his first season back following his career-threatening injury. In 2011, he posted the best walk rate of his entire career, walking just 5.1% of batters. His strikeout rate was down from career norms, but it still sat at a respectable 20.2%.  His FIP over 111.2 innings was an above average 3.21. Additionally, his swinging strike rate was up across the board, most notably the whiff rate on his fastball, which was his best since 2007 (and possibly his career; however, PITCHF/x data isn’t available before 2007). Peavy was back.

Stay tuned for Part Two, which will tie all this in with the Red Sox. Bear with me.
All stats are courtesy of and Injury information is from Sports medicine information is from Additional information was provided by Evan Brunell writing for