Pedro tops list of free-agent starters
When running through the list of free-agent pitchers, why not just focus on ERA? Because ERA lies.
Not always, of course. Not even usually. But consider Carl Pavano, who in some quarters is the most attractive and available pitcher this winter. Pavano's 2004 ERA (3.00) was significantly lower than his 2003 ERA (4.30). Ah, so he finally turned the corner. Except that if you look at everything except Pavano's ERA's in those two seasons, there's very little evidence that he was a measurably better pitcher in 2004. In both seasons, he pitched roughly the same number of innings, gave up the same number of hits and home runs, walked roughly (actually, exactly) the same number of batters, and struck out roughly the same number of batters.
The only real difference between 2003 and 2004 is that Pavano was luckier in one season than the other. And while this example perhaps does tend to the extreme, this sort of thing happens all the time, which is why you'll get burned if you don't look past ERA.