Is Donald Sterling mentally competent? Court date is set to decide.

The drama surrounding Donald Sterling and the NBA’s effort to oust him as owner of the Los Angeles Clippers entered yet another act Wednesday, as lawyers for the octogenarian billionaire and his estranged wife faced off in a Los Angeles probate court.

The issue this time is not whether Mr. Sterling is a racist or whether he should be fined or banned from the National Basketball Association for life, but whether he is competent to handle his business affairs. This high-stakes maneuvering, with a $2 billion sale of the Clippers on the line, has many wondering just what it takes to find someone mentally incompetent – and what role it is playing in this legal chess game.

On May 29, Sterling’s wife, Rochelle, inked the $2 billion sale to former Microsoft CEO Steve Ballmer without Sterling’s participation. She invoked a provision of the Sterling family trust – which actually owns the team – that allows for one partner to handle trust business if the other has been found mentally unfit.

The sale was negotiated after at least two neurologists reportedly found Mr. Sterling "mentally incapacitated" and unfit to conduct his legal and business affairs. At one point, he appeared to be going along with the sale, but on Monday, he announced he would fight it. His lawyer has hotly contested any assertion that he is not fit to handle his affairs.

Now that Sterling is fighting the sale, his wife is asking the court to validate her unilateral action and affirm mental incompetence on his part. Sterling’s lawyers have indicated they will bring in their own medical professionals to testify to his mental soundness.

A trial has been set for July 7 and is expected to last four days. For the current deal to take effect, the team has to be sold to Mr. Ballmer by July 15.

The intense legal battle now brewing shows just how difficult a finding of mental incompetence can be, says criminal defense attorney Janet Johnson, who practices in Jacksonville, Fla. “There is no pure legal standard,” she notes, which can make for messy proceedings. The decisions are usually contextual, she says, adding, “Shelly’s not trying to get him committed, just removed from doing the daily business of a multimillion-dollar trust.”

Ms. Johnson uses as an example her father, who is in his 80s and forgets many things. “That doesn’t mean he’s mentally incompetent,” she says, but that also doesn’t mean, she adds, that a man like him would be competent to handle complex business matters.

“This is an incredibly wealthy family, and the trust has been set up to protect that,” Johnson points out.

Both sides have a legal hill to climb now that the court date has been set, says Stuart Slotnick, an attorney at Buchanan Ingersoll & Rooney in New York. While there is no pure standard, there are procedures. If a relative wants to have a family member declared incompetent, the relative needs to give all interested family members and the person in question notice of the court proceeding so they can appear and either contest or join in the application.

A court will generally appoint a court evaluator who will interview all parties and make a recommendation to the judge, Mr. Slotnick notes.

Additionally, the judge will take testimony and hear evidence to determine if a person is incapacitated – or even if he or she needs a guardian, Slotnick says. A court can decide to appoint a guardian over a person’s property or over the person himself or herself. A court can also limit the powers of a guardian or expand them based upon need.

“It is not a quick and easy process,” but rather “deliberate and time consuming,” he says via e-mail.

As for why Sterling has decided to fight the sale, money is not the issue, his lawyer told the Los Angeles Times. “He doesn't want to die and have his tombstone say, ‘Here lies a mental incompetent and a racist,' ” said Maxwell Blecher, his longtime attorney. “He is trying to do the best he can to see whether those stigmas can be eliminated or at least reduced.... That is what this is about.”

His wife’s attempt to act without his consent may actually have led to his fighting the sale, Mr. Blecher suggests. "She decided to go for the mental incompetency to get rid of him,” Blecher told ESPN, adding, “I think that ticked him off.”