The Antiterrorism and Effective Death Penalty Act (AEDPA) contains a provision restricting federal courts from considering any authority other than holdings of the Supreme Court in determining whether to grant a state prisoner's petition for habeas corpus. Through an empirical study of cert filings and cases decided by the Supreme Court, we assess this provision's impact on the development of federal constitutional criminal doctrine. Before AEDPA and other restrictions on federal habeas corpus, lower federal courts and state courts contributed to doctrinal development by engaging in a "dialogue" (as described by Robert M. Cover and T. Alexander Aleinikoff in a 1977 article). This dialogue served to articulate the broad constitutional principles set forth in Supreme Court precedent. AEDPA has effectively ended the conversation, because under AEDPA federal courts lack the power to resolve emerging constitutional issues in the context of state prisoners' federal habeas petitions. Now that only Supreme Court precedent can provide the basis for federal habeas relief under AEDPA, it is more important for open questions to be presented to the Supreme Court. Unless cert is sought and granted in cases arising out of state criminal proceedings, constitutional criminal doctrine may be frozen. Current certiorari practice is out of step with this reality. Our analysis of the procedural posture of criminal cases in which certiorari was granted by the Supreme Court over the past twelve years demonstrates that, since 1995, the Supreme Court's certiorari grants in criminal cases have been tilting away from federal prisoners’ direct appeals and towards state prisoners' federal habeas and (to a lesser degree) state court direct appeals. Because the Court is not, as a general matter, using certiorari grants in state prisoners' federal habeas cases to develop doctrine, it appears that certiorari from state court direct appeals is poised to become the primary vehicle for such development. Yet an empirical analysis of certiorari petitions filed in the October 2006 Supreme Court term reveals a gap between this opportunity for doctrinal development and practitioners' current certiorari-seeking behavior. We coded 347 "paid" certiorari petitions and a sample of 300 in forma pauperis petitions, categorizing cases by procedural posture. Although certiorari grants in federal prisoners' direct appeals are declining dramatically, the leading category of cert filings remains federal prisoners' direct appeals. Given that there are far more state criminal proceedings each year than federal prosecutions, we argue these trends demonstrate an opportunity to file more and better certiorari petitions from state criminal proceedings. We urge the criminal defense community to close this "cert gap," both to ensure a better standard of review for individual clients and to promote continued development of the law.