Aggressive batter/runners on a walk, especially if the fourth ball got by the catcher, quickly round 1B and continue to 2B.

Does the Look Back Rule figure into this at all? After receiving a walk, can a player round 1B then stop and retreat back to 1B.

As long as the ball is not in the pitcher's possession within the pitching circle, there is no LBR to be in effect. Therefore, the runners can advance or retreat at their own will.

However, once the pitcher has possession of the ball within the circle, then the runner is allowed one stop, and then must immediately commit either back to the last base legally held or to the next base.

Ball 4. F2 returns the ball to F1 in the circle. BR can round 1B, run toward 2B, stop 2 inches before 2B, and then either step on 2B or return to 1B. She has not violated the LBR.

Once she reverses direction, however, she must continue non-stop back to 1B.