Ken Davidoff of Newsday is one of the few proponents of sabermetrics in the mainstream media. Unsurprisingly, he produces some of the best content around. An excerpt from his column on Frankie:
K-Rod has a 2.04 ERA in 16 appearances this season, and that and about $350 million will help you clean up the Gulf of Mexico oil spill. It's just not a very useful statistic for a reliever.
Instead, you should delve into the exciting world of sophisticated baseball analysis and check out xFIP, which factors in walks, strikeouts and fly ball rate. Heading into Wednesday, Rodriguez carried an xFIP of 4.41. That reflects the high number of fly balls he surrenders - 56.4 percent of his batted balls, before Wednesday - and the expectation that 11 percent of those will be home runs.