Leading off in baseball is the act of a baserunner getting a head start at advancing to the next base by taking steps off of the base in the direction of the next base. This can be an effective tactic for stealing base, but may result in a pickoff and tag out if the base-runner is not careful. This term should not be confused with the description of a batter batting first in an inning, known as leading off the inning.
A base runner is always either safe or unsafe relative to a base. A runner must be touching the bag with a part of his body to be considered safe. If he is advancing between bases he is unsafe. Baserunners are notorious for leading off from a base in hopes of getting an early start at advancing to the next base. If a base runner is overconfident in his leadoff, he may be susceptible to a pickoff.