How are they another piece of evidence if they aren't an effective metric? You know, I've taken statistical analysis classes and I never saw the chapter on why wins were a useful stat for measuring pitcher ability. Maybe I was gone on those days? I teach statistics. You are making an assumption that they are not an effective metric Data are data, they are neither bad nor good. They just are. It the qualitative evaluation that we do with the data that determines there fitness. In baseball wins and losses matter. Now, when judging a pitcher wins/looses are probably not the best way to judge whether or not the pitcher was effective. However, there probably is not only one metric to use. If that is the case then one has to look at other sources of evidence. Among those sources are wins, ERA, WHIP, etc. I think the best way to judge a pticher is to look at all the data and weigh evidence. What kills me here is the rigid thinking that wins are tottaly unimportant.