Force play: Meaning (information, definition, explanation, facts)

In baseball, a force play or force out, referred to as a force when the possibility of such a play exists, is a situation when one runner is compelled to advance to the next base due to the presence of runners immediately preceeding him. In this instance, a runner may be put out by a fielder in possession of the ball tagging the base to which the forced runner is advancing. The runner may be tagged out in the usual fashion as well; for the purposes of the rules, this tag is still considered a force play. Note that plays on the batter at first base are always force plays because the batter must advance there.