Bases on balls per nine innings pitched

[1] It is a measure of the bases on balls ability of a pitcher.

All but one of the top 25 single-season leaders in BB/9IP through 2018 pitched in the period of 1876-84.

[2] The highest single-season modern day baseball performance was by Carlos Silva (0.4301 in 2005).

[2] The all-time career leaders in BB/9IP through 2022 were Candy Cummings (0.4731), Tommy Bond (0.4787), and Al Spalding (0.5114), all of whom played in the 1870s and 1880s.

[3] The active career leaders in BB/9IP through 2022 were Corey Kluber (1.9683), Michael Pineda (1.9719), and Hyun Jin Ryu (1.9914).