The power to adjudicate a controversy; the legal right by which a judge presides over a case. In bankruptcy, the authority vested, sometimes in United States District Courts, and sometimes in the United States Bankruptcy Courts, to preside over cases instituted under Title 11 of the United States Code. Original, but not exclusive, jurisdiction over bankruptcy cases lies with the district courts. Jurisdiction over bankruptcy cases is proper in bankruptcy courts, which are designated as “units” of the district courts, and to which bankruptcy proceedings may be referred by the district courts. Jurisdictional issues often arise in bankruptcy courts when the resolution of a certain matter may impact upon the value of estate property, or impact upon the administration of the bankruptcy estate, although the matter itself may not involve the debtor as a party or may not involve property of the bankruptcy estate. The United States Supreme Court decision in Marshall v. Stern has cast doubt on a bankruptcy judge’s jurisdiction to enter final judgments with respect to certain counterclaims filed by a debtor against a party filing a proof of claim against the estate.