Purely based on his offense.
Most casual fans think Gross is clutch and all that jazz, but his raw stats leave a bit to be desired: .234/.337/.413 overall. Gross has had to face lefties in 52 at-bats and his lack of success pulls his numbers down a bit. Against righties Gross has a .766 OPS and outside of July each month has been solid:
You don't see 0.063 BABIPs much, even with a weak .240 xBABIP. Otherwise his numbers look pretty solid and Gross' HR/FB% is in line with his career norms. There's no reason to believe this is a fluke season, and yet I know a few have said he's overrated. I suppose that could be purely from the label we give him, which is why I'm going to offer my description of Gross:
Above average hitter (with defensive value) who should almost never hit against left-handed pitchers.