A season that began with plenty of promise has turned sour for the Mets. A case could be made for several different times as marking a spot where things went south. On April 16, the Mets entered the game against the Nats with a 12-2 record, then opened up a big lead but dropped the game 8-6. Perhaps it was May 9, when the Mets lost 2-1 to the Reds in a game where the Mets batted out of order. Then there was June 1, when the Mets lost to the Cubs 7-4, dropping below .500 for the first time, and officially squandering away their great start. However, the case could be made that an offseason move was the catalyst for Met futility in 2018.
On November 2, 2017, then Mets batting coach Kevin Long signed with the Washington Nationals as their batting coach. Reports at the time said the Mets had wanted to retain Long. Long of course had applied for the managerial job that ultimately went to Mickey Callaway, so no one could blame him for leaving after not getting the promotion he thought he deserved.
Long was the Mets batting coach for three seasons, and many players credited him with improving their hitting during that time frame. Daniel Murphy revised his stance and launch angle at the urging of Long, and went from a singles hitter to a feared power hitter in the latter part of 2015, and especially in the playoffs as the Mets made their pennant run. Neil Walker and Yoenis Cespedes, among others, credited Long for helping them become better hitters.
This year though, with Long gone, the Mets offensive production has plunged. The team slash line as of this writing is .231/.310/.382, resulting in 319 runs scored, which is good for only 26th place among MLB teams. Michael Conforto, Todd Frazier and Jay Bruce, among others, have all seriously regressed at the plate. Bruce, for example, has an OPS of just .613. As the recent open thread on this site noted, Kevin Plawecki is hitting a lot of ground balls. Long has been a strong proponent of higher launch angles, perhaps he could have helped with getting Plawecki on track for getting more batted balls into the air.
The starting pitching for the Mets has held up well. Jacob deGrom is a potential Cy Young award candidate with his league-leading 1.84 ERA. Noah Syndergaard, although limited to 11 starts so far due to injury, has a 3.06 ERA. Steven Matz has a solid ERA figure of 3.46, and although Zack Wheeler has a 4.47 ERA, he has pitched much better of late. His ERA for June was 3.26. Only fifth starter Jason Vargas has been bad.
The combination of fine starting pitching and poor batting, especially in key spots, has lead to an abundance of games where the opposition scores only one or two runs yet they still win the game. The bullpen has hurt the team, but the off seasons of so many hitters has really weighed the Mets down.