Need clarification on obstruction call

[Fritz]

Originally Posted by Klokard

At any time did the catcher block the runner from reaching the plate without the ball? If so, obstruction in FED. If not, then without being there and seeing the play, sounds like the catcher did his job. Remember, for obstruction to happen, the catcher must block all of the plate without the ball. If he offered any of the plate at all for the R3 to slide into, we have no obstruction. If the catcher received the ball prior to the slide, great play by the catcher. That's how I would have called it.

I've been told to judge obstruction on what it forces the runner to do BEFORE the fielder has the ball. In the OP, if the catcher blocking the plate in advance forced the runner to try and run around him as he neared home, even if the throw ended up beating the runner but after the runner adjusted his route, then you have OBS. Otherwise, you could find yourself in the position of calling OBS on a catcher who sets up early in the basepath, receives the throw while the runner is still 30 feet away and has to wait for the runner to show up to be tagged out. Try selling OBS in that sitch......