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;....
Does the term "away from his baseline" only mean laterally or could it mean vertically as well? If the catcher was 6ft tall..., there's your evidence right there!
