“He [Charlie Brown] was effective throughout the game and was an aggressive hitter and base runner.” “Robbed. Toledo Wins Unfairly,” Dayton News, September 5, 1898, p3
No earliest use given in 2009 Dickson Baseball Dictionary
NOTE: ” “aggressive batsman” was used at least one year before this, and both terms were used to describe cricketer players earlier in the 1890s.
