Example (force play): With a runner on first base, the batter hits the ball to the shortstop.
The runner at first base must then advance to second base as the batter is running to first base.
If the shortstop then touches second base before the runner moving to it reaches it, then that runner is out.
Example (not a force play): With a runner on first base, the batter hits the ball
to the first baseman who touches first base causing the batter to be out.
The runner moving to second base must then be tagged in order to be out.
force play
A force play occurs when a runner must move to the next base as a result of the batter becoming a runner.
The runner who must move may then be put out by a fielder (who has the ball)
touching the base the runner must move to before the runner reaches it.
A play is no longer a force play if the batter-runner is put out.
