Mark Cuban thinks daily fantasy sports is a game of skill, not luck. It's an opinion that puts the "Shark Tank" star and Dallas Mavericks owner at odds with his state's attorney general, Ken Paxton, who believes the business of companies like FanDuel and Draftkings constitutes illegal gambling. 

Paxton wrote in an opinion released Tuesday that daily fantasy sports rely too heavily on chance to be considered games of skill, thus qualifying the games as a form of betting under Texas state law. Paxton joins the New York attorney general in vocalizing opposition to increasingly popular gaming sites like DraftKings and FanDuel. New York's AG issued a cease-and-desist order against the startups in November

Frustration on the part of state officials' hasn't curbed enthusiasm from investors. Cuban, a billionaire investor who resides in Dallas, tweeted Tuesday that the Texas attorney general's views are a disappointment and "don't represent the views of Texans." Cuban recently invested in daily fantasy sports analytics platform Fantasy Labs.

Cuban zeroed in on Paxton's reference to the state's legal definition of betting, saying the definition was overly broad. Paxton cited state law in his opinion, explaining that in Texas a "bet" is defined as "an agreement to win or lose something of value solely or partially by chance."

Cuban tweeted at the state official, "isn't all biz" a form of betting by that definition? "Stocks? Collectibles? Insurance"?

"Let's be clear. More skill is required for DFS than picking stocks," Cuban said. "Luck is required to win at picking stocks," but it's not required for daily fantasy sports.

This isn't the first time Cuban has taken a swing at opponents of daily fantasy sports, a year-round version of fantasy sports games that doesn't have to adhere to sports seasons.

"The only people who think it's gambling, as opposed to skill, are people who haven't played or people who have other political agendas, because that's also very important these days," GeekWire quoted the investor as saying at a panel in Las Vegas earlier this month. 

He said that the ability to use analytics tools like Fantasy Labs to win big in DFS games means the games are truly about skill and not luck. "If it was gambling like the lottery, you wouldn't need to do that ... You would just play the game and take your chances."

"I'm saying it's not luck if you know it's coming and is deterministic," he tweeted Tuesday.

The investor's statements echoed defenses used by DraftKings and FanDuel.

He claimed his stake in daily fantasy sports was too low to be considered a source of bias. He estimated the total value of his investments and ad revenue at less than $1 million.

"I can walk way from it. It has nothing to do (with) my position," he said.