@Corey Burnett - yesYes that is the rule a runner must stay within 3 feet of the baseline per Rule 7.08:
"7.08 Any runner is out when— (a) (1) He runs more than three feet away from his baseline to avoid being tagged unless his action is to avoid interference with a fielder fielding a batted ball. A runner’s baseline is established when the tag attempt occurs and is a straight line from the runner to the base he is attempting to reach safely"
Any runner is out when— (a) (1) He runs more than three feet away from his baseline to avoid being tagged unless his action is to avoid interference with a fielder fielding a batted ball. A runner’s baseline is established when the tag attempt occurs and is a straight line from the runner to the base he is attempting to reach safely
Reference: http://www.mlb.com/mlb/downloads/y2007/07_the_runner.pdf
