Following a steep decline at the plate in August and September 2012, Brian McCann decided at least in part against the Atlanta Braves' estimations to undergo shoulder surgery in October to repair his torn labrum. The surgery required about six months of rehab, which meant McCann could not return to the lineup until May 2013, when he showed off his new pain-free swing by belting six homers in a .911 OPS month.
After making his seventh All-Star team, however, McCann would struggle to find consistency in the final months of the season:
Thankfully for McCann, the Yankees thought highly enough of his body of work to sign him to a five-year, $85 million deal during the offseason. McCann rewarded their faith by struggling badly to start off 2014, recording only a single hit in his first 16 at-bats in Yankee Stadium, before finally breaking out and batting somewhat normally in August and September.
Questions over whether he was pushing to clear the right field wall were misguided, as he seemed to be hitting the ball as hard as ever. Nonetheless, the new ballpark, coaching staff, and increasing defensive awareness of his tendency to pull the ball combined to force McCann to change his approach:
The biggest takeaway that jumps out from the above chart, courtesy of BrooksBaseball, is that McCann has been slowly weening himself off breaking balls since 2009, when he swung at more than 45% of them. In the six subsequent seasons, McCann has gradually cut that number by more than 10 points to about 34.6% in 2015.
McCann has made a similarly drastic cut in his swing percentage on offspeed pitches, but that adjustment is more notable because he has done it in one-third the time. As recently as 2013, his final season in Atlanta, McCann offered at 51.3% of offspeed pitches. In 2014 he cut that number to 46.3% before finally bringing it down to 41.6% in 2015. These numbers only tell part of the story of McCann's adjustments:
The above chart, courtesy of FanGraphs, shows that in addition to swinging at fewer offspeed and breaking pitches as time has worn on, McCann has swung at significantly fewer pitches inside the strike zone (Z-Swing%) and has swung significantly more at pitches outside the strike zone (O-Swing%). After starting his career consistently offering at strikes 68-73% of his chances, McCann has settled around 60% in the past several years in the former category, while he has improved from swinging at one in every five balls to one in every three. Generally speaking, McCann takes more pitches.
Combined with the specific pitch information, one can glean that McCann has adjusted his plate approach to maximize his power by swinging at a higher ratio of fastballs with continually eroding regard whether they would be called strikes. But why would McCann adjust his approach during such an impressive offensive run beginning in 2006? The answer is the proliferation of the infield shift, which has decimated McCann's batting average on balls in play (BABIP):
The well-documented explosion in infield shifts from the 2010 season through 2013 and beyond, lies very closely on top of McCann's decline. Intuitively, as he watched more and more of his hits of yesteryear sail directly into the mitts of shifted third basemen, he realized he needed to adjust his approach to continue to produce.
Thanks to the shift, McCann began to swing at a higher ratio of fastballs while taking a higher ratio of offspeed and breaking pitches. With an increased focus on one type of pitch McCann has been able to swing harder at fastballs, which has resulted in a modest increase in home run percentage, as well as become better at identifying and taking slower stuff, which has resulted in a modest increase in walk percentage. Even during his terrible 2014, when he was pushing at the plate, his line drive percentage has also been up in recent seasons.
In terms of what to expect going forward, McCann will continue to adjust to ever-increasing infield shifts by taking more pitches he could put somewhere in the infield (offspeed and breaking pitches) while swinging at more pitches he can hit out of the yard (fastballs). He should continue both striking out and walking more frequently on slower pitches while making contact on fastballs that seem impossible to use. Expect McCann's BABIP to rise modestly, if at all, as he focuses more closely on his on-base numbers and slugging.