The relevant information to answer the above question is: The act of blocking the plate accounted for most of the physical contact in Major League Baseball prior to the 2014 season, when it was outlawed except when the catcher already has possession of the ball.is the reasoning for what question and answer pair?
Q: In baseball, blocking the plate is a technique performed by a catcher to prevent a runner from scoring. The act of blocking the plate accounted for most of the physical contact in Major League Baseball prior to the 2014 season, when it was outlawed except when the catcher already has possession of the ball.

Based on this passage, can the catcher block the plate in mlb?
A: it was outlawed except when the catcher already has possession of the ball