Rule 10. Considerations Governing Review on Certiorari http://www.supremecourt.gov/ctrules/...oftheCourt.pdf
Review on a writ of certiorari is not a matter of right, but of judicial discretion. A petition for a writ of certiorari will be granted only for compelling reasons. The following, al*though neither controlling nor fully measuring the Court’s discretion, indicate the character of the reasons the Court considers:
(a) a United States court of appeals has entered a deci*sion in conflict with the decision of another United States court of appeals on the same important matter; has decided an important federal question in a way that conflicts with a decision by a state court of last resort;
or has so far departed from the accepted and usual course of judicial proceedings, or sanctioned such a de*parture by a lower court, as to call for an exercise of this Court’s supervisory power;
(b) a state court of last resort has decided an impor*tant federal question in a way that conflicts with the decision of another state court of last resort or of a United States court of appeals;
(c) a state court or a United States court of appeals has decided an important question of federal law that has not been, but should be, settled by this Court, or has decided an important federal question in a way that conflicts with relevant decisions of this Court.
A petition for a writ of certiorari is rarely granted when the asserted error consists of erroneous factual findings or the misapplication of a properly stated rule of law.