After signing Mike Jacobs to a minor-league contract, the Mets will enter Spring Training with 5 firstbaseman, who, if not exactly in a competition, all have some shot at the major league roster. Stepping back first, though, signing Mike Jacobs makes no sense. There is no team in the major leagues that Mike Jacobs improves by being on the active roster. In the best case scenario, Jacobs comes off the bench and hits an unusual number of homeruns in an extremely small sample size, a la his 11 homeruns in 30 games in 2005. Even then, the value he bleeds whenever playing a few innings in the field, coupled with the opportunity cost of keeping a potentially more versatile, useful player on the bench makes him pretty pointless. Even in the Mets' situation, he will end up taking playing time away from one of Ike Davis, Nick Evans, or Chris Carter, all of whose development is more important to the Mets than whatever minuscule value Jacobs provides to the Buffalo Bisons.
Still, I held off criticizing this signing at first because many people just seem eager to slam the team for any small move, and really, Mike Jacobs, the Bison, is not that significant. In the link above, Heyman insinuates the Mets view Jacobs as a potential starter and he reiterated as much on twitter. I am going to assume that is purely speculation based on some remark a Mets official made about doubting Murphy in another context. Many people dismay at the idea of Francoeur starting, but at least he can field and hit for average. Mike Jacobs succeeds only at hitting homeruns and fitting Dykstra-esque amounts of chaw in his mouth.
Probably, though, Daniel Murphy will enter Spring Training the presumptive starter. Much has been said about Murphy this offseason and most of it rings overzealous. Last year the debate over whether or not entrusting Murphy with leftfield made any sense created a situation where someone had to be right and someone wrong. In that way, Murphy's 2009 seemed unfairly like an absolute test of his skill in many people's eyes. 2009 did not go well, therefore all of those positive reports from Spring Training, the hype about his work ethic, Jerry's proclamation that he was a better hitter than Church and his 2008 call-up was all a veneer hiding an unspectacular player. Maybe. Yes, he had that fluky BABIP in 2008, but only because he was hitting an unsustainable amount of linedrives, not by some incredible string of luck. When I looked at Murphy's adjustments in the second half of last year, I became less certain of what caliber a hitter he'll be. He made improvements, but with caveats. His ability to hit inside fastballs improved greatly, but he demonstrated little ability to discriminate against fastballs right outside of the inner-zone. So will Murphy be an improved hitter in 2010? Probably, but to what extent depends on Daniel Murphy. Anyone who claims to know whether "first-half" or "second-half Murphy" will "show up" this season is probably just reiterating some bias they formed after 2008.
Somewhat conservatively, I'll default to CHONE's projection of Murphy as a .330 wOBA--exactly average--hitter. Looking at this projection, many people will say one of two things: he's a suitable stop-gap for Ike Davis and/or he does not have the bat to play first. The notion of Murphy as Ike Davis' stopgap bothers me, because it implies both that Murphy has some stable level of production we can live with for a season and that Ike Davis is a sure thing. Neither are true--anyone who assumes Ike Davis is destined for stardom is setting themselves up for disappointment. Without getting too much into a prospect discussion, Ike is very good, but with some kinks and is not yet exactly banging on the door. Also, there remains a significant, non-zero chance Murphy ends up the better firstbaseman. My reasoning here relates to why I think the "firstbase is for your masher" concept is a little antiquated.
Most reading this article probably accept the fangraphs WAR model, or something close to it. Then you probably believe that David Dejesus, Nyjer Morgan, and Carl Crawford are very good left fielders, despite not being among the best hitters at their position. You probably see what I'm getting at, and may be thinking firstbase is an even less important defensive position, making this analogy a little tenuous. This disparity in importance, though, is reflected in a harsher positional adjustment and in the generally lower UZR scores for the top firstbasemen versus the top leftfielders. Yet, nearly every season (the last being a notable exception), a first baseman or two will add 1 WAR worth of value in fielding. Making a statement about Murphy's defense based on similar metrics last year would be pointless; they are nowhere near the necessary sample size to drawn conclusions. Yet, if leading the league in Dewan's plus/minus after a half season and then working with Keith Hernandez in the offseason does not portend a potentially elite defensive firstbaseman, nothing does.
Chris Carter is the darkhorse here, but defense will probably keep him out the majors. Evans might also see AAA with the similar Fernando Tatis re-signed. Clearly, I'm firmly in the Murphy camp and I don't think his splits are such that he needs to straight-platoon with Tatis.