[bigwally]

The plate umpire needs to clear the catcher and keep his eye on the ball in case it gets mishandled or accidently kicked into dead ball territory. Moving to third base would have the plate umpire taking his eye off the ball, running with his back to the ball and having no idea when or where the throw is coming from. That puts him in a precarious situation. The base umpire needs to hustle around second and on to third to make that call. He would have all the elements of the play in front of him. He can see the ball, he can see when its thrown and he has the runner and the base in front of him. He may not acquire the angle the home plate umpire would have by coming up the line but thats a small concession considering the other advantages the base umpire has. That being said, in certain situations when the ball and catcher cooperate and plate umpire can safely, without interfering with the play get to third base, I see no problem with him calling for the play at 3rd otherwise this is the base umpires call