1911 Encyclopædia Britannica, Volume 3… (1911)
“ Base-running is one of the important arts of base-ball play. A good base-runner takes as long a lead off the base as he dares, starts to run the moment the pitcher makes the first movement to deliver the ball, and if necessary throws himself with a slide, either feet or head first, on to the objective base, the reason for the slide being to make it more difficult for the baseman to touch the runner, having to stoop in order to do so, thus losing time. A base-runner is out if he interferes with an opponent while the latter is fielding a ball or if he is hit by a batted ball. ”
