2. More importantly what does the signing do for the Mets?
Immediately, the 31-year-old Bay will improve the Mets left field position. In 699 plate appearances in 2009, Mets LF hit .276/.352/.421 with 35 2B, 9 3B and just 12 HR. In 2009 for Boston, Bay hit .267/.384/.537 with 29 2B and a career-high 36 home runs. Bay's ability to get on base and hit for power will be welcome additions to the Mets lineup.
However, Mets pitchers, should reasonably fear Bay's work in right field at Citi Field. Bay's Ultimate Zone Rating in 2009 was -13. By UZR's calculations, he has cost his team at least 10 runs afield every year since 2007, and the only year in which he has been a positive contributor defensively was 2006. Clay Davenport's system also rates Bay as a below average defender. Moreover, he's likely to become a worse defender as he ages.
Value vs. Holliday
The Mets have reportedly signed Bay for $66 million over four years ($16.5 million annually) with an "easy" vesting option for the fifth year that will push the deal's total value to roughly $80 million. As Dave Studeman points out, Bay fit the Mets need for both a left fielder and a power hitter. To me, the Mets' needs, and market considerations, render the analysis here at Fangraphs which calls the signing a "significant overpay" based on a market value of $3.5 million per WAR, a little limited. The Mets needed a left fielder who hits for power. They needed a player who can help them make a run at the Phillies.
The question for me is whether the money they spent on Bay would have been better spent on Matt Holliday. Following Bay's signing, ESPN reported that Holliday's agent, Scott Boras, is now asking teams for roughly $18 million dollars annually, or $1.5 more than the Mets are paying Bay.
If the ESPN report is accurate, the Mets will be paying nearly top dollar for the second best player on the market, for a similar contract length. That's not good. To recap here are Bay and Holliday's WAR valuations since 2005:
Keith Law argues that Fenway's Green monster makes Bay appear worse defensively than he actually is. However, he ranked as a below average defender even before he reached Boston. By contrast, among LF with more than 600 innings, Holliday was the seventh best defender this past season and has been consistently above average.
Even if you accept Law's argument, that fielding statistics generated in left field at Fenway Park are invalid, Holliday still outperforms Bay when examining only the two players' offensive contributions. Take a look at the following table which examines the two by VORP, which is measured in runs not wins, and considers only a player's offense, for the last four years:
Is the signing entirely explained by the fact that the Mets are enamored of Jason Bay's pull approach? Hittracker.com, has the scatter plots of the true ending distances for all of Jason Bay and Matt Holliday's 2009 homeruns. The scatterplot for Bay comes first. All but five of Bay's homeruns were hit to the left of straightaway center field, and most were pulled towards the left-field corner.
Matt Holliday's scatter chart follows. Unlike Bay, Holliday uses the whole field to hit his home runs.
Here are all of the home runs hit at Citi Field in 2009:
Citi Field looks like it would cost both ballplayers some long balls. Primarily, it would cost Bay on balls hit into the left-field corner and it would cost Holliday on balls to right center. Is this a significant enough reason to prefer Bay over Holliday? Not for me it's not.
What does the Bay signing tell us about how the Mets view the future of prospects Ike Davis and Fernando Martinez? Probably not much. On the other hand, it indicates that the team realizes that it can not count on Jeff Francoeur repeating his Mets half of the 2009 season. Martinez, who will be 21 to start 2010, now looks headed for Buffalo, where he will try to stay healthy for the first time in a full season. Should Francouer return to his below replacement level struggles that marked his time before the Mets, and Martinez is hitting in AAA, he will return for his second chance in the big leagues. Also likely, Ike Davis will join Fernando Martinez to start 2010 at Buffalo. Unless the Mets add a first baseman, Davis has a chance to hit his way into the New York lineup during the 2010 season.
Long-term, the presence of both Davis and Martinez potentially limits the Mets options with Bay. In theory, the Mets could move Bay to firstbase at the end of his contract to mitigate his poor defense in left field. However, Mets fans expect Davis to be the Mets starting first baseman by 2011 or even by late 2010. Davis's potential ascendance would keep Bay in the outfield. On the other hand, Davis who played in the outfield for the US team at the baseball World Cup this fall, could potentially move to the outfield to accommodate Bay. Shifting players in this manner hardly seems like the recipe for replicating the strong team defense which helped carry the Mets in 2007 and 2008.
I have been a fan of Jason Bay for a long time. However, he was not the best leftfielder on the market this winter, that honor belonged to Matt Holliday. As it now stands, Holliday appears to be poised to make more money than Bay, both on a per anum basis and on the lifetime of the contract.