Even though the Supreme Court will not return to the bench for another month, the white marble building has begun to hum. Or rather, to sweat.

Now is when the justices, their clerks, news reporters and some lawyers get serious about sorting through more than a thousand petitions that came in during the summer recess and are being considered for the term that begins on the "First Monday" in October.

Deadlines loom. Life becomes The List, a mind-boggling compilation of about 1,750 cases that have been appealed from lower courts around the country. The List is backed by close to a ton of legal briefs, some printed on elegant paper from premier law firms, some written with pencil on lined stock from prison inmates. But all are long shots. Only about 1 percent of the cases that land on the court's doorstep are accepted for review each year.

In the oak-paneled chambers, amid exquisite paintings and custom-made furniture, the justices and their clerks systematically (and sometimes frantically) sift through appeals. A total of 7,000 cases arrive at the high court each year, but the screening process is most daunting after the recess when so many "petitions for certiorari," as they are called, have stacked up and when the law clerks are newly hired. About a fourth of the court's annual caseload rests on The List.

The clerks do the spadework, writing memos recommending which cases should be heard. An important yardstick is whether the lower courts have decided similar legal questions differently. If these splits aren't resolved, people in various parts of the country live under effectively different rules.

"It's tricky," said Stuart Benjamin, a former clerk to Justice David H. Souter. "Some litigants know the buzzwords and write that there's a 'split in the circuits,' even 'a deep and clear split in the circuits.' You have to go back to the lower court opinions and see just how true that is."

All of the justices except John Paul Stevens rely on a "pooling" system for culling the petitions. Their clerks work together on memos about the cases. (Stevens's clerks make their recommendations on their own.) The pooled approach is a relatively new phenomenon in the court's two-century history and not without its critics.

Chief Justice William H. Rehnquist said that when he first came to the court in 1972 there was no "cert pool," but he soon helped create one and defended it in his 1987 book about the court: "Recently I was asked whether or not the use of the law clerks in a cert pool didn't represent the abandonment of the justices' responsibilities to a sort of internal bureaucracy. I certainly do not think so. The individual justices are of course quite free to disregard whatever recommendation" is made.

As the chief justice sees it, a standard set of criteria go into choosing which cases will be heard--a far different situation than when a case is actually decided on the merits. "[T]here are really only two or three factors comprised in the certiorari decision," Rehnquist wrote, "conflict with other courts, general importance, and perception that the decision is wrong in the light of Supreme Court precedent."

But even these criteria can be interpreted differently and it is not easy to predict which cases will be granted a hearing--as reporters who try to prepare The List know well. The fate of most cases on it will be made public on a single day, the first Monday in October. So reporters spend weeks on The List, trying to anticipate which cases will be accepted--immediately elevating a dispute to national significance--and which will be denied, meaning the end of the line.

A spurned appeal can be equally newsworthy, such as when the court last fall refused to hear a Wisconsin dispute over school "choice" programs that use taxpayer money to send poor children to religious schools. The justices left in place a Wisconsin court ruling that vouchers do not violate the Constitution's prohibition on government policies that promote religion. Their action meant more legal uncertainty and politicking in the other states.

"It's a potentially deep pit for the unprepared," said Associated Press reporter Richard Carelli, who has covered the court for 23 years. "It takes us more than a month to sift through the cases on The List." He said the wire service typically puts out 50 to 60 stories on a first Monday in October.

The justices will make their final choices in secret at a Sept. 27 conference, in a small chandeliered room. No clerks or other staff are there. Four votes are needed to hear an appeal. Most petitions are rejected without any discussion. But a handful will be taken, scheduled for oral arguments in upcoming months. And in just a few hours, the summer List will be history.