Five years ago today, the Supreme Court overturned the Professional and Amateur Sports Protection Act, launching what has become a massive legal sports betting industry.

Why it matters: The booming business has become inescapable to fans, littering TV broadcasts with ads and driving the conversation in sports bars across America.

State of play: Since the bill was overturned, Americans have legally wagered over $220 billion on sports, generating over $17 billion in revenue for sportsbooks and $3 billion in state and local taxes.

• 33 states (plus Washington, D.C.) have live, legal markets, four states have legalized betting but haven't begun operations, and another six have active legislation or ballot initiatives.
• Every major league has official betting partners, and 11 different pro stadiums have or are planning in-venue sportsbooks.

Between the lines: There are dozens of sportsbook operators. But in the 12-month period ending Feb. 2023, four accounted for nearly 90% of the U.S. market, per gambling analytics firm Eilers & Krejcik.

• FanDuel: 46%
• DraftKings: 25%
• BetMGM: 12%
• Caesars: 6.7%

The big picture: A brief snapshot of the industry’s explosive growth…

• May 2018-April 2019: $8.3 billion wagered, eight new markets launched.
• May 2019-April 2020: $13.7 billion, nine new markets launched.
• May 2020-April 2021: $34 billion, five new markets launched.
• May 2021-April 2022: $74.2 billion, nine new markets launched.
• May 2022-April 2023: $90.4 billion, three new markets launched.

What to watch: The three most populous states in the nation — California, Texas and Florida — still don't have legal sports betting markets.

• That should change at some point, given those three states are home to 32 of the 124 (26%) teams in the major North American leagues.

Reality check: It could be a while. Texas has a pair of active bills, but little support in the state Senate.

• California saw a pair of costly propositions fail last fall.
• Florida is engaged in legal battles with the Seminole tribe, which claims to have exclusive rights to gaming in the state.

The bottom line: Five years ago, sports betting was limited largely to Las Vegas. Now, over half of American adults live in a state where they can bet legally — often from the comfort of their couch.

Editor's note: Most states have only reported numbers through March, and five states — New Mexico, Washington, North Dakota, Wisconsin and North Carolina — do not make total wager amounts publicly available.