Is Obstruction Mental?

[reccer]

The simple part is understanding the intent of the defensive player setting up astride the base line 2 feet in front of the base.

The difficult part is judging whether a runner traveling at 2.5 feet per tenth of a second is reacting to the defensive player.

(math is assuming runner is already at full speed coming around third and heading home)

Maybe you give the catcher some leeway if the runner is trying to score from second. The runner's path may take her to backside of plate. However, runner starting from third and heading home will be taking direct line. No reason catcher is setting up in baseline for this play. Call obstruction.