Out of baseline

[Jerry]

OBR 7.08 (a)(1) "Any runner is out when he runs more than three feet away from a DIRECT LINE BETWEEN BASES to avoid being tagged . . . ."

In your scenario, the "base line" is a direct line between 3rd base and home. While you are correct that a runner establishes his own baseline (a direct line from where he's at to where he's going), he cannot be more than 3ft from a direct line between bases for purposes of avoiding a tag. A fielder with the ball in hand does not need to chase a runner all over the diamond in order to tag him. As described, the runner in your case should have been called "out" for being out of the baseline on an attempted tag.