It's no secret that the Yankees offense this season has been worlds better than it was last year. In the midst of the resurgence of Mark Teixeira and Alex Rodriguez, Brian McCann's return to being an above-average hitter has been lost a bit in the shuffle. The Yankees threw big money at McCann before the 2014 season, and while he wasn't bad last year with the bat - and brought a ton of value to the game as a pitch-caller and framer - he certainly wasn't the offensive upgrade the Yankees hoped he would be. This year, however, McCann has reclaimed his place as one of the best overall catchers in the big leagues, posting the fourth highest fWAR and the third highest wRC+ of qualified catchers, behind only Buster Posey and Stephen Vogt. In 2015, McCann is rewarding the Yankees' belief that he would remain an elite catcher in his 30s, and his turnaround at the plate has been a big part of the Yankees' return to being a team competing for the playoffs.
McCann's improvement is due to a variety of factors. He is popping up far less often (FanGraphs has a great deep dive on this that I highly recommend everyone read), he is hitting the ball harder, and he is also performing much better in high leverage situations and situations with runners on base. His improvement against righties, however, has perhaps been the biggest factor in his resurgence. Since there are more right-handed pitchers than lefties, this makes a lot of sense. Both his wRC+ and his OPS against right-handed pitchers have made huge jumps this season from last - his wRC+ is 118 (up from just 76 last season), and his OPS is 150 points higher (.805 now compared to .633 in 2014).
McCann has been pulling the ball more this year - more, in fact, than he's done in any other season. This change has a lot to do with McCann limiting his attempts to hit the ball the other way (presumably away from the shift). Last year, he swung at more pitches in the strike zone, all over the strike zone. He especially swung a lot at pitches outside, perhaps in an attempt to rope them the other way and away from the shift:
This season, he's become much more patient, forcing pitchers to come to him with the pitch he can pull for power - the pitch up and in. McCann has made a marked jump in the swings percentage on these pitches, wasting fewer swings on strikes down and in, and away as well:
This strategy has helped him pull the ball more this year, and is much more in line with how he's swung throughout his career. Instead of trying to beat the shift, McCann is back to waiting for pitches to pull and drive, which has helped catapult his offensive numbers back to where fans expected they would be when he signed with the Yankees - and back to where they've generally been during his time in the big leagues, showing that 2013 was probably an aberration. His swing is made for the short porch in right field, and this year, he's waiting for the perfect pitch to put in those right field seats. It's a big reason why McCann is back to being one of the best hitting catchers in the majors, and why the Yankees have a great chance to get back to the playoffs this year.