The Astros had their worst season in franchise history this past season. Bad pitching certainly had a lot to do with that.
Yet, as the franchise celebrates 50 years (and only 50) in the National League this season, we can look back fondly on some great pitchers. Twenty seems like such an arbitrary place to cut it off, but when you look at the numbers, it makes a lot of sense.
It is often hard to compare eras, but sabermetrics allows us to do that through some advanced statistics. One of those statistics is called ERA+. It compares ERAs from different eras against the league average.
It allows for differences in era and differences in home ballparks. So, an Astro who enjoyed the spacious Astrodome in the 1970s can be compared to a pitcher that dealt with the band box that is Minute Maid Park.
Pitchers with ERA+s over 100 are considered to be better than the league average. Those with scores under 100 are below average. We took only pitchers with scores of 101 or higher. They had to pitch for either five years or amass 500 or more innings as Astros.