John Mayberry Jr. was once a regular in the Phillies' lineups. Between 2012 and 2013, he played in 283 games, posting a slash line of .237/.294/.393. Last season, though, he moved to the bench, and he was the best pinch-hitter in baseball. In 32 plate appearances, first for Philadelphia and then the Toronto Blue Jays, Mayberry hit .400/.438/.933 with four doubles and four home runs. Despite the small sample size, his power numbers, specifically his ISO (.533) and home run to fly ball ratio (44.4%), were too incredible not to post.
While it has been covered extensively this offseason that production for pinch-hitters is difficult to predict from one season to the next, Mayberry has shown a career-long penchant for producing in the role. In 121 career plate appearances as a pinch-hitter, Mayberry has posted a line of .304/.355/.545 with a 145 wRC+. His power output as a pinch-hitter has been tremendous, with seven home runs, a .241 ISO, and an excellent 23.3% home run to fly ball ratio. In 2011, he had seven extra-base hits in 35 plate appearances; in 2012, he had seven extra-base hits in 23 plate appearances.
Both as a pinch-hitter and position player, Mayberry will likely see time strictly against left-handers, due his severe career splits. Mayberry has been abysmal versus right-handers (.658 OPS and 81 wRC+), but outstanding against left-handers (.857 OPS and 130 wRC+).
Looking to 2015, Mayberry has struggled at Citi Field. In 103 career plate appearances, he has seven extra-base hits and a line of .208/.262/.323. His 62 tOPS+ is the worst mark of his career in any stadium in which he has at least 40 plate appearances. In 2014, the Mets as a team struggled against left-handers (.633 OPS) and when pinch-hitting (.544 OPS). Despite his struggles in Queens, Mayberry's strengths as a hitter should make him a valuable asset to an improved Mets lineup.