Will Jason Bay's power return?

The last time I watched Jason Bay play on a nightly basis was the 2009 season, his last in Boston before departing to New York with a four-year, $66 million contract. A full season removed from his time in Boston, the image of him punishing line drives to left-center or hitting moon balls over the Green Monster still sit fresh in my mind.

Unfortunately for Mets fans, they aren’t quite able to muster up such memories.

Over his season and a half in Boston, Bay hit 45 home runs or one home run every 16 at-bats. His career before coming to Boston, Bay went yard at an equally impressive clip of once every 18.5 at-bats. But in his first season in Flushing Meadows, Bay’s power stroke all but disappeared in the caverns of Citi Field as he managed only six home runs in nearly 350 chances -- or once every 58 at-bats.

To be fair to Bay, his season was undoubtedly cut short by injury after his July 25 concussion that landed him on the 60-day disabled list. As a streaky power hitter adjusting to a new park with the pressure of a new contract, Bay could very well have turned his season around in 2010 if healthy. Robbed of that chance by the Dodger Stadium wall, Bay turns to the 2011 season to make amends.

"I just want to get back to the player I know I am," Bay told reporters in Mets camp. "I kind of lost that a little bit last year."

Two questions immediately come to mind upon hearing Bay’s words: 1) Can Jason Bay regain his past form and become a threat in the middle of the New York Mets’ lineup; and 2) What exactly did he lose last year that sapped his power in the first place?

Surely the move from Fenway Park to Citi Field had its impact on Bay early in 2010. My memories of Bay and his assault of -- and over -- the Green Monster are validated by a quick look at the scatter plots of his home runs over the course of 2009 when 24 of his 36 home runs cleared the Monster.

But Fenway Park alone didn’t make Bay a dangerous pull hitter. Over the course of his career, nearly half of his extra-base hits have been pulled to left field. While Bay wasn’t likely to turn in consecutive years with an ISO of .466 on pulled balls like he did at Fenway, and some regression upon leaving for any new home would be expected, Bay still owned a career .304 ISO on balls hit to left.

What happened last year? He simply stopped pulling the ball as often and with as much power. In fact, he turned into a virtual Alex Cora at the plate, posting an ISO of .079 on pulled balls to Cora’s .073. Not what you expect from your $66 million slugger. Is it fair to place the full blame of his power lapse on ballpark factors? No. But if there were a case that exacerbated the impacts of park changes more than this, I would be surprised.

Given Bay’s ability to find his power stroke to left in 2011, can he translate that into a 30-plus home-run season? According to Bay, at least, he has a shot.

""Thirty, I think, is reasonable," Bay said. "That's a big ballpark, and the number might take a hit, but you look at David Wright. David hit 29, and it can be done."

Unfortunately for Bay, you won’t find a major projection system or the voting community at FanGraphs as optimistic about a return to the home run leaderboard.

2011 Home Run Projections: Jason Bay:

FanGraphs Community: 23

ZiPS: 20

Bill James: 21

Marcel: 17

Then again, maybe Bay is an eternal optimist after all.

"Are we going to win 120 games?" Bay asked. "I don't know, but I think we're going to be a lot better than people think."

Tim Daloisio contributes to Fire Brand of the American League, a blog about the Boston Red Sox.