We'll keep track of changes in his ROY odds in this file.
All odds courtesy of Caesars Sportsbook.
Rookie of the Year odds
Caesars posted ROY odds on June 18, two days before the 2019 NBA draft. As the projected No. 1 pick, Williamson opened as the prohibitive odds-on favorite at -450. "Zion is a giant favorite, but I don't know if it's big enough. It's one of those things if I take a max bet, then I might go [much higher]," Caesars head of risk Jeff Davis told ESPN at the time. Memphis Grizzlies guard Ja Morant and New York Knicks guard RJ Barrett had the next-best odds at +450. The three represented the top three picks of the NBA draft.
In his fourth preseason game, Williamson apparently injures his knee and several days later it's announced that he will miss the start of the 2019-20 season with a knee injury. Morant becomes the betting favorite on Oct. 29, with Williamson falling to the third-best odds.
Odds (Oct. 29):
Odds (Jan. 22):
After Williamson's exhilarating debut Wednesday night, Caesars shortened his odds to 8-1 (tied with Nunn), with Morant still the favorite at 1-7. According to ESPN Stats & Information data, no player has won the award playing fewer than 50 games. The maximum number of games Williamson can play this regular season is 38.
Odds (Jan. 23):
Zion Williamson cut into Ja Morant's odds after Williamson and the Pelicans beat the Grizzlies 139-111. Williamson had 24 points in that win, while Morant had 16. The Pelicans outscored the Grizzlies by 25 points when Williamson was on the court. He also became the second rookie in NBA history to score at least 10 points and shoot above 50 percent in each of his first five games according to the Elias Sports Bureau (Cedrick Hordges).
Odds (Feb. 1)
After another brilliant game from Williamson where he scored 21 points on 9-for-11 shooting against the Bulls, Williamson moved to +250. The performance moved his field goal percentage to 57.4%, the best through eight games by any rookie since Hakeem Olajuwon in 1984-85.
Odds (Feb. 7)
Williamson sat out the night before against the Pacers, but he still cut into Morant's odds, moving to 2-to-1, his shortest odds since the start of the season.
Odds (Feb. 9)
One day later, it was Morant's turn to have a big game with 27 points, 10 rebounds and 10 assists, his first career triple-double. He became the first rookie this season with a triple-double and the second Grizzlies rookie to do it, joining Shareef Abdur-Rahim in 1997. That moved Morant back up to a -650 favorite. These odds held through the All-Star Break, despite Williamson having back-to-back 30-point games in his final two games before the break.