It's all about getting an edge.

Two years ago, when partners at the Schnader Harrison law firm first began talking about setting up a consulting business aimed at lawyers who need help sharpening appeals-court arguments, a threshold question was whether it would make money.

The jury is still out on that, but the consulting business is up and running. And the initial response suggests that in the rarified world of appellate law, there's a market for expert advice on tailoring briefs and oral arguments.

Schnader Harrison Segal & Lewis L.L.P. began advising outside lawyers on appeals cases through its Bernard G. Segal Institute for Appellate Advocacy in February, and it so far has had a slow but steady trickle of engagements.

Last week, it held its main kickoff event, a mock court at the National Constitution Center featuring a panel of judges who serve on its advisory board, including former Whitewater prosecutor Kenneth Starr and former FBI director William Webster.

Nancy Winkelman, executive director of the institute and cochairwoman of Schnader's appellate-practice group, said the practice of appellate law had become so specialized that many firms could benefit from outside advice.

"The legal community recognizes that the appellate practice is a distinct legal specialty," she said. "Appellate-level clients and trial lawyers are recognizing that it takes some unique skills."

She added, "I am not a black-and-white person; I see gray a lot. I don't see the gray in this."

Named for the late Bernard Segal, a former Schnader partner who was highly regarded for his appellate work, the institute was patterned in part after mock courts at the Georgetown University Law Center that prepare lawyers for arguments before the U.S. Supreme Court.

Winkelman herself tested an argument before the Georgetown panel in 2002 in advance of arguing a case before the Supreme Court. She said there was a stark contrast between the Georgetown panel and another mock court composed of colleagues and other lawyers she knew, where she also tested her arguments.

The Georgetown panel was tough, whereas lawyers who work with you are more likely to be deferential and to pull punches, she said.

Too often, she says, lawyers seeking to prepare for such cases turn in-house for help, where they are less likely to get an objective reaction.

"The Segal Institute lends a level of detachment and neutrality, so that a lawyer coming in to argue doesn't have professional relationships with the judges, or financial relationships with the judges," Winkelman said. "It's as close to an actual court as it can be."

The institute, a wholly owned subsidiary of Schnader Harrison, is in keeping with a growing trend by law firms to establish subsidiary businesses that, while somewhat removed from the firms' core missions, seek new ways to capitalize on law firms' talent pools.

One other recent example is the announcement by Duane Morris L.L.P., another Philadelphia law firm, that it had established a separate trust company to advise affluent clients seeking to move offshore assets to the United States.

For the moment, Winkelman said, mock court aimed at testing a lawyer's oral arguments forms the core of the Segal Institute's work. To best gauge a lawyer's chances in an appellate case, Winkelman said, the institute seeks former judges from the court where the case will be heard to sit on the mock court.

Typically, the mock court would also include a lawyer with long experience practicing in the district where the case will be heard, and an academic or lawyer deeply knowledgeable about the underlying issues.

The firm has established a separate database to help screen out participants who might have conflicts.

The firm reimburses these experts at their hourly rate, and clients of the institute pay the Schnader law firm a fee that is a set percentage of the cost of the outside experts.

So far, most of the firm's clients have cases that are fairly well along, meaning that most are seeking assistance in shaping their oral arguments, the endgame in an appellate case.

Winkelman said the firm hoped to eventually begin assisting clients much earlier in the process by helping them write briefs. More than oral arguments, Winkelman said, the briefs generally are decisive in determining whether the case will be won or lost.

The aim is to review the briefs in the same way an appellate judge would and then make the needed changes - before the real court sees them.

"Writing the briefs in the most persuasive way possible is a skill," Winkelman said, "and it is a skill that not all lawyers have."

Contact staff writer Chris Mondics at 215-854-5757 or cmondics@phillynews.com.