BetMGM wins dispute over "past-posted" wagers at the Bellagio

The Nevada Gaming Control Board has ruled in favor of the BetMGM sportsbook in a dispute over dozens of past-posted parlay wagers made at the Bellagio in June.

The decision will allow BetMGM to void more than $200,000 in outstanding parlay bets that were placed by a group of bettors in the early-morning hours between 1:30-3:30 a.m. PT on June 28 on the self-serve kiosks at Bellagio in Las Vegas and on the sportsbook's mobile betting app, ESPN reports. The parlays included KBO League and Chinese Professional Baseball League games that had already started, but were left available for betting because of a bookmaker's error, according to ROAR Digital, the company that operates BetMGM sports betting.

Some bettors were able to cash tickets before the sportsbook realized the error and could stop payments. All the outstanding bets will be rescinded. An MGM spokesperson on Wednesday confirmed to ESPN that they had received approval from the Nevada Gaming Control Board and will rescind and refund the wagers in question. 

Neither BetMGM's house rules in Nevada or NGC regulations include language explicitly addressing bets placed on events that have already started, which is commonly referred to as "past-posting" in the sports betting and horse racing communities. NGC regulations prohibit sportsbooks from unilaterally rescinding wagers without written approval from gaming control.

Traditionally, situations involving past-posting for modest amounts were settled amicably, with sportsbooks offering to pay the bet but refusing to take further action from the customer, or refunding the bet and continuing to allow the bettor to play. 

Betting on Korean baseball increased in popularity during the coronavirus pandemic with most major U.S. sports halted. The games air mostly overnight in the U.S. All four of the Korean baseball games that were included in the parlay tickets began at 1 a.m. and ended before 4 a.m. PT.