What is the dropped third strike rule?

If a runner tries to avoid a tag and runs more than three feet outside of the base path, the runner is out automatically. Is the base path the line between the bases? No, the base path is the direct line between the base and the runner at the time when the fielder is trying to tag the runner. The base path is the direct line between the runner and the base to which she is either attempting to advance or retreat at the moment that a defensive player is attempting to tag her. Moreover, the base path may be a long way from the base line. For example, a batter who realizes that the third strike was dropped may start running from near the entrance to the bench. Does running out of the base path always result in an out? In general, runners may run well outside of the base line. For example, if a runner is advancing more than one base, she is able to run faster by rounding the bases rather than slowing down to cut sharp corners. However, the base path rule applies if a tag play is being made on the runner. What about first base? There is an additional rule when running to first base. The batter should run in the "runners lane," which is a three-foot wide path on the foul side of the first base line; the lane starts halfway from home plate to first base and runs to the orange (outside) bag at first base. If the batter runs outside of the lane and is hit by a throw or interferes with a fielder's effort to catch a throw at first, the batter will be called out.

An Infield Fly is a fair fly ball (not a line drive or bunt) that, in the judgment of the umpire, can be caught by an infielder, pitcher, or catcher with ordinary effort and when there are runners on first and second or first, second, and third and less than two outs. When the umpire calls "infield fly” the batter is out, regardless of whether the ball is subsequently caught or dropped. The ball is live, and runners already on base may advance (at their own risk) if the ball is not caught or tag up and advance if it is caught. Simply put - it's in effect if there is a force at 3rd base with less than two outs. Why does it exist? To prevent double or triple plays on popups. Imagine bases loaded and a soft popup to third base. Without the infield fly rule, the runners have a dilemma. If they stay close to their bases, the third base player could choose to let the ball drop and get multiple outs by tagging the runner who was on third, stepping on third base to force out the runner from second, and throwing to second base to force out the runner from first. If the runners go too far from their bases, the third base player catches the ball and doubles them off. The reason the rule applies only with at least first and second base occupied is that if there are not multiple runners on base, a missed popup can only result in one force out.

When a fielder does not have the ball and is not in the act of fielding a batted ball, an obstruction occurs if that fielder impedes the progress of a base runner. The umpire makes an obstruction signal by extending the left arm to the side with a fist. If the impeded runner is put out prior to reaching the next base or a subsequent base that the umpire believes she would have reached if the obstruction had not occurred, then the out does not count and the umpire will put the runner on the base she would have reached absent the obstruction. It is very important to understand that the ball remains live after obstruction occurs and that the runner must try to advance in order to get the base to which she is entitled. When the umpire lowers his or her arm, the runner is no longer protected, either because she has arrived at the base she would have reached or she has failed to try to advance. What does it mean for the player? As fielders, players have a hard time learning to stay out of the way of runners. We see obstruction called in almost every game, and the most common obstruction comes from a fielder standing on a base without the ball when the runner reaches the base. If a fielder is playing directly between two bases when the ball is pitched, she needs to be prepared to move out of the way of a base runner if the ball isn't hit to her. After a ball is hit, if there is no play at her base, then she needs to stay away from the base and out of the runner's way. A runner (as well as the coaches) should look for an obstruction signal by the umpire if she's impeded, and she should continue running to the next base even if a tag is likely. As long as the umpire is making the obstruction signal, the runner is protected in advancing.