Why can't the Mets do it on the road?

Last night's debacle in San Diego underscores the Mets' lopsided record this season: 19-9 at home, 8-18 on the road. On May 27, Joe Lapointe's New York Times "Bats" blog post gave the manager's theory:

Manager Jerry Manuel said he was not sure why the team played so poorly on the road but speculated that it might be because they get excited by smaller ballparks away from Citi Field and try to hit home runs.

This squares with my long-held belief that the Mets are a team perennially afflicted with what might be called "wannabe-a-hero" syndrome. This could also explain their frustrating inability to get hits in "clutch" situations.

Sean Forman looked further into the question of home field advantage in general in his "Bats" post later that same day. A statistical study, Forman writes, has shown that having the last at-bat is not what gives the home team the edge. Instead, it's familiarity with the idiosyncracies of the "friendly confines". This advantage is enhanced when a team's home field is in its second through fifth year of use. When a team first uses a new field, the players must learn its peculiarities just as those on visiting teams must, so the advantage is reduced. After the fifth year, visitors have come to learn the territory, which again reduces, though it doesn't negate, the home team's upper hand. Since Citi Field is now in its second year, this could at least partially explain the Mets' superb record at home, but not why they're so dismal away.

6.6 update: The at-home magic is back as the Mets complete a sweep of division rivals the Marlins.