[Andy]

Haven't heard of this one.

I have been taught to trail the BR with no runners on or with a runner on first only. With a runner on second or beyond, I will step back and look down the first baseline extended to have the angle on the play at first, then release to third base to cover any play there.

I would say that trailing down the line gives you a good angle to see the pulled foot, swipe tag, etc., no matter which way the defensive player is pulled by a throw. If you are out toward the PP and a throw pulls F3 in a direction that she is stretching straight toward you, you are straightlined and not able to offer much help to your partner. Of course, in that case, the BU may have a better angle due to the off-target throw.

Some UICs like to try something new or different from time to time, Perhaps your UIC had enough confidence in your abilities to ask you to try this change and give him some honest feedback.