The baseball world officially met Francisco Rodriguez in October 2002 when, thanks to a loophole in MLB's postseason roster rules, Rodriguez was added to the Angels' ledger for their ALDS series against the Yankees. A few weeks later the Angels had won their first World Series title and the legend of K-Rod was born.
Rodriguez is a free agent now and has some kind of reputation as a big game pitcher -- at least, I've read that a few times lately -- but I don't know whether that's really true. It is true that he was almost unhittable in 2002, but he hasn't been especially dominant in five playoff series since then.
Neither set of data is a particularly large sample, but there's hardly conclusive evidence that Rodriguez is any sort of big game pitcher, and it might be easier to make an argument to the contrary. I won't suggest that he should be judged by his last thirteen postseason innings, but he certainly shouldn't get any bonus points for being a playoff star since reality doesn't seem to support that particular assertion.