NBA Last 90 will go into effect during the 2019-20 season:
"NBA Last 90 players will have the ability to wager on various outcomes, including which team will win, who will score on the first possession and the total number of points scored by both teams, during the last 90 seconds of a simulated matchup between two NBA teams. A vast archive of NBA highlights and footage will be randomly pulled from any matchup over recent seasons between the two teams, producing millions of possible outcomes."
The NBA has been proactive on the sports betting front.
Commissioner Adam Silver penned an op-ed in the New York Times in November 2014 making the case to legalize sports gambling. He explained his opinion further during an appearance on ESPN's Get Up! in April 2018, saying he thought it made sense to bring betting on basketball out into the open.
The U.S. Supreme Court in May 2018 overturned the Professional and Amateur Sports Protection Act, paving the way for states to make their own decisions regarding the practice. Eight states have legalized sports betting, with another seven weighing legislation on that front.
Last July the NBA announced it struck a deal with MGM Resorts to make MGM the league's official gaming partner.
Silver has said he thought sports betting would allow fans to be more engaged with the NBA because they'd have something financially invested in the action. Scott Kaufman-Ross, head of fantasy and gaming for the NBA, echoed a similar point to ESPN.com's David Purdum regarding NBA Last 90.
"We've been looking at this the past couple years and were really surprised to see how popular this was," Kaufman-Ross said. "In Europe, we're especially excited about using virtual as another way to engage with our fans with alternative content, especially given the time-zone challenges we have in the region."
The NBA will be the first major American sports league that will offer fans the chance to bet on simulated games.