In
baseball, a
force is a situation when a
baserunner is compelled (or
forced) to vacate his
time-of-pitch base—and thus try to advance to the next base—because the
batter became a runner. A runner at
first base is always forced to attempt to advance to
second base when the batter becomes a runner. Runners at second or
third base are forced only when all bases preceding their time-of-pitch base are occupied by other baserunners and the batter becomes a runner.