Baseball Field - Baseline

A baseline is the direct route—a straight line— between two adjacent bases, though it is not drawn in chalk or paint on the field (though foul lines are drawn). The basepath is the region within three feet (0.9 m) of the baseline. Baserunners are not required to run in this objective basepath, however; a baserunner may run wherever he wants when no play is being attempted on him. At the moment the defense begins to attempt a tag on him, his running baseline is established as a direct line from his current position to the base which he is trying for. A runner straying more than three feet away from his baseline in an attempt to avoid a tag may be called out.