[Updated 9:20 p.m. ET: Mayweather is favored 1/2; Pacquiao is favored 8/5]

Just hours before their fight at the MGM Grand in Las Vegas, Floyd Mayweather is still the decided favorite against Manny Pacquiao. While the betting odds vary slightly at different sports books, all of the oddsmakers have given Mayweather the best chance of winning the most profitable bout in boxing history.

At the betting website Bovada.lv, Mayweather has -200 odds, and Pacquiao has +160 odds. Mayweather is a -200 favorite at Sportsbook.ag, as well, though Pacquiao is getting +170 odds. The odds are -200 and +170 at the MGM Grand sports book in Las Vegas.

The most likely outcome is a Mayweather victory by decision, which has been the result in seven of Mayweather’s last eight fights. The second and third most likely outcomes, oddsmakers say, are wins either by decision or knockout for Pacquiao. A draw is considered to be the most unlikely finish.

Pacquiao’s odds have improved since the fight was made official in February. When it looked like the bout might happen in 2010, Mayweather was actually the underdog. But Pacquiao has been defeated twice since then and has recorded no knockout victories. Mayweather still hasn’t lost in his career.

An early round knockout victory for Pacquiao would be the worst-case scenario for Las Vegas sports books. If the fight ends in a decision, the oddsmakers will be rooting for Mayweather.

The megafight, along with other sporting events, will make May 2 one of the biggest Saturdays for Las Vegas sports books in recent memory. A few hours before Mayweather and Pacquiao finally meet, the Kentucky Derby will get underway. One hour before the pay-per-view begins, the San Antonio Spurs and Los Angeles Clippers will face off in Game 7 of their first-round playoff series. The New York Yankees vs. Boston Red Sox and NHL playoffs are also featured on Saturday.