In baseball statistics, hits per nine innings (denoted by H/9) is the average number of hits allowed by a pitcher in a nine inning period; calculated as: (hits allowed x 9) / innings pitched.[1] This is a measure of a pitcher's success based on the number of all outs he records.
Compared to a pitcher's batting average against, a pitcher's H/9 benefits from sacrifice bunts, double plays, runners caught stealing, and outfield assists, but it is hurt by some errors. Unlike batting average against, a pitcher's H/9 benefits from outs that are not related to official at bats, as they are recorded on runners after they have reached base.
Through 2019 Nolan Ryan is the career leader, at 6.5553, while Clayton Kershaw is # 2 (6.7856), and Sandy Koufax is # 3 (6.7916).[2]
See also
References