They wrote it better than I: Sabermetrics Manifesto To put it simply, sabermetrics is simply an attempt to acquire objective knowledge about baseball through facts, or statistics. It looks at only things that can be completely quantified, and it looks to try to quantify things that can't (the "little things", so to say). Sabermetric stats are an attempt to measure the complete value of an individual. No statistic is perfect, so the best statistics are those that minimize flaws. Most of sabermetrics is focused on hitting, as ERA for pitching is a fairly accurate enough measure of individual ability. Since things like runs, RBI, and wins are largely dependent on others, they are regarded minimally as is, in favor of other statistics. Also, counting stats are problematic because, obviously, the more chances, the higher count (on average). Stuff like Win Shares exist to try to compare players from different eras and doing different things (hitting, pitching, fielding) as accurately as possible. EDIT: I will say, however, that my biggest criticisms of most sabermetrics is that they undervalue the strikeout as an out (basically by passing it off as the exact same as any other type of out for a hitter, but oddly they value it more for pitchers), and how they pass off anything specifically unexplainable as "luck", when it's simply a combination of immeasurable factors.