NEW YORK (Reuters) - Jeffrey Kessler may not be a household name. But when his signature appears on a lawsuit against a major sports organization, league officials know they are up against a hard-nosed litigator who has built a career taking on sports' most powerful interests.
Kessler's latest clients are five stars of the World Cup champion U.S. women's soccer team, who have sued the national governing body because they make far less money than the men's national team despite generating more revenue.
But over three decades of litigation, he has gone after all four major U.S. professional sports leagues, the National Collegiate Athletic Association and the Olympic Games, among others. His assertive manner has achieved results, even as it has sometimes rubbed his opponents the wrong way.
"I grew up in Brooklyn," Kessler, 62, said in a phone interview on Thursday. "I have my style. But I also bring a passion to what I do. If that style and passion sometimes can be a little aggressive, I'm not going to apologize for that."
He has worked on some of the most famous, and infamous, cases in sports. Last year, he secured the reversal of National Football League star quarterback Tom Brady's so-called "Deflategate" suspension over allegations he was part of a conspiracy to deflate balls to his advantage before a playoff game.
Kessler also represented running back Ray Rice in his successful appeal of an indefinite suspension in 2014 for punching his fiancée, and helped quarterback Michael Vick keep millions of dollars in bonus money after his 2007 conviction for running a dog-fighting ring.
In 2008, he won a verdict allowing the double-amputee sprinter Oscar Pistorius of South Africa to compete in the Olympic Games against able-bodied runners.
"He's certainly caused a lot of sleepless nights for a lot of people," said Gary Roberts, a sports law professor and dean emeritus at Indiana University's law school. "In virtually all of his lawsuits, he is challenging something that at one time not long before that, everyone just took for granted."
Kessler, a partner at New York law firm Winston & Strawn, says a common theme runs throughout his work.
"I have consistently been involved in representing athletes in their struggle against owners that don't recognize their rights and economic worth," he said.
Kessler's expertise is in antitrust law, which has spawned most of his best known cases. In 1992, he won a jury verdict on behalf of NFL player Freeman McNeil that helped pave the way for modern free agency, leading to a massive rise in salaries.
Kessler is spearheading a lawsuit in California challenging the amateurism structure of the NCAA, which restricts the amount of money college athletes can collect in financial aid.
"These cases against the NCAA are potentially going to change the whole model of collegiate athletics," said Marissa Pollick, an attorney and lecturer of sports law at the University of Michigan.
Kessler's style - in court he speaks with volume, both in sound and in words, and he often employs tough rhetoric in public comments – does not always endear him to his adversaries.
In 2011, during contentious contract talks, Kessler accused the NBA of treating its players like "plantation workers," a comment for which he would later apologize.
Then-Commissioner David Stern said Kessler's conduct was "routinely despicable" and called him the "single most divisive force in our negotiations."
Kessler is a sports fan but would not say which teams he roots for to avoid any perception of bias.
Although he received a hero's welcome from fans when he attended the New England Patriots' 2015 season opener after Brady's suspension was overturned, Kessler said fans have occasionally accused him of favoring one team or another.
Asked about the cases of which he is most proud, Kessler cited the McNeil verdict against the NFL and the Pistorius case. He said that case opened doors for disabled athletes, even though Pistorius himself was later convicted of murder.
Kessler said his biggest regret was losing an antitrust lawsuit against Major League Soccer in 2000 on behalf of players seeking higher salaries.
"I'm still thinking about that one," he said. "I don't like to lose."
Additional reporting by Mica Rosenberg; editing by Grant McCool