PU Hold while BU(s) position or Both back in simulataneously

[IRISHMAFIA]

Originally Posted by ronald

What is its meaning? Serious question as have never heard why it is there.

From ASA:

Many years ago the Look Back Rule was established to help speed-up the game by stopping the pitcher and the runner from “toying” with each other when the ball was being returned to the infield after it had been put in play. The rule was not established for the offense or defense to gain an advantage through “trick plays” or by “baiting” the other side into a violation.