A minimum of four of the nine Justices are required to grant a writ of certiorari, referred to as the "rule of four". The court denies the vast majority of petitions and thus leaves the decision of the lower court to stand without review; it takes roughly 80 to 150 cases each term. In the term that was most recently-concluded as of 9 June 2009, for example, 8,241 petitions were filed, with a grant rate of approximately 1.1%... The Supreme Court is generally careful to choose only cases over which the Court has jurisdiction and which the Court considers sufficiently important, such as cases involving deep constitutional questions, to merit the use of its limited resources...

...The granting of a writ does not necessarily mean that the Supreme Court disagrees with the decision of the lower court. Granting a writ of certiorari means merely that at least four of the Justices have determined that the circumstances described in the petition are sufficient to warrant review by the Court. Conversely, the Supreme Court's denial of a petition for a writ of certiorari is sometimes misunderstood to mean that the Supreme Court approves the decision of the lower court. Such a denial "imports no expression of opinion upon the merits of the case, as the bar has been told many times." Missouri v. Jenkins, 515 U.S. 70 (1995). In particular, a denial of a writ of certiorari means that no binding precedent is created by the denial itself, and that the lower court's decision is treated as mandatory authority only within the region of jurisdiction of that court.