Runner coliding with Catcher While Fielding a Thrown Ball

[Atl Blue]

Which rules? In LL and NCAA, the catcher (or any fielder) must be IN POSSESSION of the ball, or the actions you described would be obstruction.

In straight OBR, if the catcher was in position to field the ball which was about to arrive (a distance which varies, and is a judgment call), then his play was legal. If he was blocking the plate and the ball was not about to arrive, obstruction.

In FED, the arrival of the ball must be "imminent" (again, a judgment call) in order for the fielder to block the base, otherwise obstruction.

So when you said "major league" game, if you are talking about MLB type of "major leagues" and not the LL version of "major leagues", if the ump judged the catcher were about to field the ball (typically judged to be a throw in the infield on a direct path to the catcher), then the block was legal. But so is the plowing by the runner, an act banned in some way in most amatuer leagues.