A federal judge on Friday partially certified a lawsuit filed by more than 20 players, allowing football and basketball players in major programs to challenge as a group NCAA rules prohibiting compensation beyond the value of their athletic scholarships, but also denying their pursuit of billions of dollars in past revenues.

In her long-awaited, 24-page report, U.S. District Judge Claudia Wilken carved a pathway for fundamental change in the economic model of college sports in a ruling that will help college athletes in their arguments to receive a share of television and other media revenues.

The ruling also minimized the prospect of forcing the NCAA to pay billions of dollars in past damages to players who may have been wronged under anti-trust law. Players can still sue for damages, but only as individuals.

The mixed ruling left both sides claiming victory in statements sent to ESPN.

"The court's decision is a victory for all current and former student-athletes who are seeking compensation on a going forward basis," said Michael Hausfeld, lead attorney for the players. "While we are disappointed that the court did not permit the athletes to seek past damages as a group, we are nevertheless hopeful that the court's decision will cause the NCAA to reconsider its business practices."

The NCAA addressed only the side of the judge's decision it favors. The governing body for college sports had been accused by the plaintiffs of working with member institutions to fix at the price of zero the amount of Division I basketball players and Football Bowl Subdivision players could receive as players.

"We have long maintained that the plaintiffs in this matter are wrong on the facts and wrong on the law," said Donald Remy, NCAA chief counsel. "This ruling is one step closer to validating that position."

On balance, the NCAA fared worse because the ruling opens the doors for players to assert their rights as contributors to the business of college sports, said Rob Carey, a lawyer who represents former Arizona State quarterback Sam Keller and other players in a related, but separate aspect of the case tied to publicity rights.

"This ruling increases the likelihood that wholesale change will occur in college sports," Carey told ESPN. "It's like Major League Baseball when free agency came along."

Ultimately, Wilken increased the likelihood that any ruling she makes will survive an appeal by the NCAA, Carey said. That's because she is addressing future distribution of revenues, rather than asking schools and athletic departments to come up with potentially billions of dollars in damages.

Wilken wrote that the players' lawyers in the case -- known as the Ed O'Bannon lawsuit because the former UCLA star is one of 25 plaintiffs signed on -- failed to provide a solid method for determining which members were in the class, and which players EA Sports build avatars for in its virtual game environment. They also failed to determine which players appeared on game rosters in TV games.

"We are pleased that the court correctly found that conducting a class-wide trial for claimed damages for student-athletes who played college football and men's basketball going back nearly a decade would be completely unmanageable and unprecedented," Remy wrote in his statement. "The plaintiffs in this case were seeking substantial damages based on erroneous theories for maintaining a class. The Court correctly removed these claims from this case."

At the same time, Wilken mostly sided with the plaintiffs in her ruling, which also codified Hausfeld as the lead attorney in a case that was originally filed in 2009.

"Plaintiffs seek certification to pursue an injunction barring the NCAA from prohibiting current and former student-athletes from entering into group licensing deals for the use of their names, images, and likenesses in videogames and game broadcasts," Wilken wrote. "Their request for this injunction is not merely ancillary to their demand for damages.

"Rather, it is deemed necessary to eliminate the restraints that the NCAA has allegedly imposed on competition in the relevant markets. Without the requested injunctive relief, all class members -- including both current and former student-athletes -- would potentially be subject to ongoing antitrust harms resulting from the continued unauthorized use of their names, images, and likenesses. Because an injunction would offer all class members 'uniform relief' from this harm ... class certification is appropriate."

Under the ruling, players would have to wait until their college careers are over with to collect on media revenues that have accrued but not shared, Carey said. He said it increases the likelihood that the NCAA will want to settle with the plaintiffs, given the potential dangers of going to trial.

Wilken set a case management conference of Feb. 20 for the two sides to gather, after each files briefs responding to her ruling. A trial is set for next June.