Buster Posey Promoted

The wait is finally over.

The Giants promoted Buster Posey to the major leagues today. Day two of September 2009 becomes a day of joyous occasion for Giants fans who grew tired of Bengie Molina’s .261/.281/.437 line through nearly 500 plate appearances. Molina’s allergy of walks is shared by back-up Eli Whiteside.

Obviously differences between the majors and minors exist when it comes to drawing a walk, still, consider that the Giants backstops have a combined 554 plate appearances and 18 walks this season. Meanwhile Posey has just fewer than 550 plate appearances throughout the minor leagues while boasting 70 walks.

Assuming the Giants plop him into the lineup immediately and Posey hits to a league average (meaning an absolutely average MLB hitter, not NL catcher) tune rather than the .321/.391/.511 line in Triple-A Fresno, he’s still a pretty nice upgrade to add this late in the year. With a game separating the Giants and Rockies in the wild card race, any kind of upgrade at this point helps. Do the basic math and assume Posey takes 100 plate appearances away from the bumbling duo and the upgrade is a little less than two runs.

Notice we’re dealing with 100 plate appearances though. That’s a pretty small sample size and anything can happen within a stretch that leaves Posey looking better or worse than league average. It’s not impossible that Posey could actually finish with a worse line than his lacking counterparts. I know, outlandish right? But Matt Wieters is proof that sometimes phenoms don’t light the league on fire immediately:

Wieters: .263/.309/.372
Giants Putrid Crew: .257/.283/.409

Of course that’s not park adjusted or league adjusted, so there’s room for improvement in that comparison. My warning for Giants fans is to not take these 100 (or however many) plate appearances too seriously. Oh, and to not pin the playoff hopes on top of his shoulders.

That being said, I’m cheering for a Giants post-season berth. The folks on the east coast need to experience Tim Lincecum.