Cody Ross is likely best when used in a reserve role. But that's best-case scenario, and not necessarily a statement that claims he should never hold down a position on his own. Over the last four years, he's been the primary outfielder at his position for two different teams, and hit .261/.321/.445 with positive defensive contributions while doing it. That might not seem like much, but he's also done that while in pitcher's parks that aren't great for right-handed hitters.
Now Ross is in Fenway, the first hitter's park he's had access to on a regular basis in his career. He's not a pure home run hitter, either, as he's the kind of guy who has doubles power with the ability to go deep anywhere from a dozen to 20-plus times. Not only is Fenway a hitter's park, but it's famous for its ability to turn guys with doubles potential into highly productive hitters. Ross is very likely the next of those guys to get this kind of benefit.
Ross isn't great against right-handers, the pitchers he would face roughly three-quarters of the time should he play every day, but he's also not bad against them:
|sOPS vs. LHP||sOPS vs. RHP|
sOPS is split-adjusted OPS; it's essentially OPS+, but broken down in specific splits. In 2008, Ross was eight percent better against right-handed hitters than your typical righty, and also mashed lefties much better than his fellow right-handers. He's been around the average or a bit better the entirety of his full-time playing career, and, except for last year's oddity out in San Francisco, always destroyed southpaws.
He faced them just 110 times, though, and a whole lot can happen in 110 plate appearances. It's why when it comes to splits, we like to look at multiple years of data. He might have hit just .234/.336/.362 against left-handers in 2011, but in his career, the 31-year-old is at .283/.349/.563. That's likely more representative of the lefty-mashing he'll do in 2012 with the Red Sox, and that's fine news for a team that has to face CC Sabathia, David Price, Brian Matusz and others on a regular basis.
Will the production against righties be enough for him to play full-time, rather than to let Ryan Sweeney in on a straight platoon? Because of his defensive value, the fact Ross is just about average against righties should be okay, especially given how potent the lineup around him is. And nothing says he needs to play every single game against right-handers, either: Sweeney is around, and when Ryan Kalish is ready, he's an option to start taking some of those plate appearances away.
The Red Sox could probably squeeze a few more runs out by using a straight platoon, but Ross against righties isn't all that different than Sweeney against them, given Sweeney's real defense lies in his glove. Sweeney is a career .296/.352/.402 hitter against righties, while Ross is at .253/.313/.414. The on-base difference could force the Red Sox to make a switch eventually, but if Ross and Fenway take a liking to each other, that might not be a problem after all.
It's likely the Red Sox (and this website) would be more forceful about a platoon if Sweeney had the kind of numbers against righties that Ross does against southpaws (this is where Kalish comes in to play). but as he's something of a singles hitter that draws walks and plays quality defense, Sweeney ends up making sense in a reserve role than as the primary starter, at least in this park. He has plenty of uses, and getting him back in the Andrew Bailey trade made a lot of sense given the injury issues the outfield depth in this organization has had the last two years. But it's for that reason that he doesn't need to start to contribute.