You can use ERA when you have around 400 IP worth of data, before that it just doesn't really say very much. As many other posters have pointed out its a flawed stat for judging a pitcher with a small sample because so much of it is out of his control. Specific to Capuano here are his numbers 2006 - 7.08 K/G, 1.91 BB/G, 10.5% HR/FB, 39.9% GB, 4.09 FIP 2007 - 7.63 K/G, 3.76 BB/G, 10.6% HR/FB, 45.8% GB, 4.39 FIP Career - 7.30 K/G, 3.08 BB/G, 11.8% HR/FB, 40.1% GB, 4.60 FIP As you can see his stats are pretty close to his career stats which would be a 4.27 ERA over 640 IP. His 4.78 ERA on the year is a bit flukish based on a little bit high BABIP and low LOB%. He's actually pitched better in 2006 and as good in 2007 as he did in 2005, he just had a flukish LOB% in 2005 to get that 3.99 ERA. He's always had a problem with consistency, he'll dominate for a few starts then lose his control and get hit around a bit.