The halakha prohibits a judge from distorting judgment in favor of one of the litigants, based on the verse: “You shall not distort judgment, you shall not give preference” (Deuteronomy 16:19). The halakhic authorities discuss how the halakha of this mishna, which allows litigants to select their own judges, can be implemented without compromising their objectivity. The Rosh explains that the judge does not do all he can in order to enable the litigant who selected him to win the case. He is certainly prohibited from acting as a lawyer does for a client, advancing a claim that he knows to be incorrect, even if the other judges would accept it. Rather, he must carefully weigh the legitimate claims of the party who selected him, and present those claims in a clear manner to the third judge. When each of the selected judges presents their considerations before the third judge, the ruling will be clarified better than if a judge had not made any effort to present the claim of the litigant who selected him.