Justice Elena Kagan extended the deadline every time she was asked last term, Mr. Bickell said, and Chief Justice John G. Roberts Jr. and Justices Thomas, Samuel A. Alito Jr. and Sonia Sotomayor did so more than 90 percent of the time. Justices Ruth Bader Ginsburg and Anthony M. Kennedy granted extensions about three-quarters of the time.
Mr. Bickell did not say how Justice Stephen G. Breyer is on this score, but he said Justice Scalia is strict.
“Anyone want to take a guess?” Mr. Bickell asked. “Four percent,” he said, and there were groans from the assembled lawyers.
“Doesn’t happen very often, so keep that in mind,” Mr. Bickell said.