The decision by a federal judge in New York to vacate the four-game suspension imposed by the NFL on Tom Brady and allow the New England Patriots quarterback to play raises legal questions about the league's disciplinary process, the role of courts in arbitration decisions and the NFL's appeal of the decision:

Q: Was the court's decision in favor of Brady and against the NFL a surprise?

A: It was certainly a surprise to me. I predicted an easy victory for the league.

Under powerful legal precedents, a federal judge ordinarily defers to the decisions of an arbitrator who, like NFL commissioner Roger Goodell, serves under a collective bargaining agreement between two parties. U.S. District Judge Richard M. Berman even noted this usual outcome in his decision. And the precedents are why Goodell and the league's attorneys refused to settle with Brady and insisted on pushing Berman into a decision. But like the reversals of arbitrators' decisions in the Ray Rice, Adrian Peterson and Bountygate cases, the judge found what he thought were significant flaws in the league's processing of the investigation and in Goodell's decision confirming the four-game suspension.

Q: What is the significance of this decision?

A: It is an obvious triumph for Brady, but it is a highly significant victory for the NFL Players Association and its lead lawyer, Jeffrey Kessler.

The law that protects arbitrators' decisions from judicial interference is a fundamental principle of American labor law. Goodell, in contrast to his bungling of the Rice, Peterson and Bountygate investigations, led a process that produced a solid investigation. Goodell's 20-page decision was impressive in its analysis of the evidence and its application of the "conduct detrimental" clauses of the CBA and the standard player contract. It was a vast improvement over Goodell's phlegmatic and occasionally incoherent testimony in the Rice arbitrations. And Brady blundered badly when he refused to cooperate with the investigation and destroyed evidence.

But the union was steadfast in its support of Brady, and Kessler and his team discerned flaws in the process that proved to be persuasive to Berman. The NFL has appealed Brady's victory to a higher court, so Berman's ruling as a trial court judge is not precedent-setting. That stated, should Brady win the appeal, the appellate court decision would be precedent-setting and would significantly diminish the NFL commissioner's power under the collective bargaining agreement.

The Brady victory was a fine bit of leadership from the union and a stunning piece of lawyering from Kessler and the Winston & Strawn firm. This was not an easy case.

Q: What arguments were the keys?

A: Berman ruled that the NFL had failed to provide "notice" to Brady that being "generally aware" of deflated balls was a form of misconduct and that obstructing an investigation was a second form of misconduct. The lack-of-notice idea looked as if it was something the Brady legal team had tossed against the wall to see if it would stick. Law professors and other legal analysts, including me, were not impressed with the argument.

Both the collective bargaining agreement and the standard player contract give the commissioner total authority to decide the definition of "conduct detrimental" to the league and to determine punishment for any such behavior. With this broad authority, it seemed that the league had no responsibility to specify forms of misconduct for its players and could levy any punishment it wished.

Following the arguments from Kessler to the letter, Berman ruled that Brady had no reason to expect punishment for withholding and destroying evidence. An argument from Brady's attorneys seemingly made only in the absence of a more powerful argument actually proved to be the turning point for Berman.

Q: The league announced it will appeal the ruling, so what happens now and what are the league's chances?

A: The league says it will not ask a court for the suspension to be upheld as it appeals the case, so Brady can play immediately. But there are reasons the league can and probably will succeed in its appeal of Berman's ruling: