on-base average (1931)

“In 26 times at bat here this trip he [Babe Ruth] made 10 hits, drew eight walks for an on-base average of .555.” George Kirksey, United Press, “Babe Ruth Wants to Turn Manager for ’34 Race,” Montana Standard (Butte, MT), August 27, 1931, p11
NOTE: This syndicated story appeared in many other papers as well, but without the term “on-base” ahead of “average.”