How Is the Composition of  a Court Determined? 

כיצד נקבע הרכב בית המשפט?

The Talmud proceeds to clarify the ruling in the mishna according to the opinion of the Rabbis, who disagree with Rabbi Meir. 

The Gemara cites an excerpt from the mishna. We learned in the mishna: And the Rabbis say: The two judges who were chosen choose one more for themselves. The Gemara asks: If it enters your mind to interpret the mishna as we said before, that “one” refers to one court, is it possible that after each court was disqualified by one of the litigants, as each party is able to disqualify the court chosen by the other side, that the members of both courts can go and choose another court for themselves? It is illogical that judges who have been disqualified from judgment, for whatever reason, will be the ones who select the court that will ultimately try the case.