How Is the Composition of  a Court Determined? 

כיצד נקבע הרכב בית המשפט?

The Talmud presents a different explanation of the mishna, in light of the difficulties it raised against the previous interpretation. 

Rather, the term “one” is not referring to the court, and instead it means one judge, and this is what the mishna is saying; this is how the entire sentence in the mishna should be explained: When this litigant chooses one judge for himself, before whom he requests to be judged, and that litigant chooses one other judge for himself, to be a member of that tribunal, the two judges then choose one additional judge for themselves as the third judge on the court. According to this interpretation, the selection of the court is achieved in two stages: First, each side chooses the judge he prefers, and then the two judges jointly select the third member of the tribunal.