Baseman/ˈbeɪsmən/ Definition 1 of 1Pro Tip 1/3Baseball Specific Used exclusively in the context of baseball or softball games. The second baseman practiced turning double plays before the game. Pro Tip 2/3Positional Roles Each baseman has distinct responsibilities depending on their base. The first baseman is often involved in force outs at first base. Pro Tip 3/3Defensive Players Basemen primarily play defensive roles, preventing the other team from scoring. The third baseman guarded the line against extra-base hits.