OttoC at SoSH has a thread this morning that takes a quick look at this issue.
There has been some talk about Quality Starts on this list. There has been criticism -- 3 earned runs in 6 innings is equivalent to a 4.50 ERA; it only counts earned runs, not all runs. I've postulated in another thread that Quality Plus Starts (QS+) where the run criterion is reduced to two, or fewer runs in 6+ innings might prove a better metric.OttoC looked at starting pitcher logs from 1957 to end of August 2007.
Quality Starts were recorded in about 51.5% of the games with the starter having a .736 winning percentage in them. ERA: 1.91. Avg IP: 7.56.Matsuzaka has 17 Quality Starts (15 of which would be QS+); for Beckett it's 13 of 16.
About 76% of the Quality Starts were Quality-plus Starts with the starter having a .792 winning percentage in them. ERA: 1.36. Avg IP: 7.67.
... although the Quality Start metric is frequently maligned, the numbers show that when a pitcher records one, it most often represents a very good start. So much so that my effort with Quality-plus Starts is not really needed.