I agree with mrtwinsfan on this one. It is only reasonable to plan on the defense not making the play, and hustle out of the box and presume you can make it. That is a professional. Or it should be. But you are right, "most batter-runners" fail at this. Admiring the deep fly that isn't a homer, the fly that is dropped and they could have been on second or third instead of first, etc. What else do they have to do? Walk back to the bench. May as well give it all the energy you can when your turn comes up. Always.