The New York Knicks and Philadelphia 76ers enhanced their rosters this summer, but the Boston Celtics remain the consensus betting favorites to win the championship entering the NBA season.

Boston has been the preseason title favorite for three consecutive seasons. The defending-champion Celtics are the favorites at +290 at ESPN BET, their shortest preseason title odds in the past three years.

Boston has the most interest from bettors at U.S. sportsbooks. FanDuel reported Tuesday that 43% of the money bet on the sportsbook's NBA championship odds was on the Celtics. The preseason favorites have won nine of the past 16 NBA championships.

The Oklahoma City Thunder, the favorites in the Western Conference, have the second-best title odds at +675, followed by the Knicks (+700) and 76ers (+825).

The Knicks' title odds shortened through the offseason, moving from +1800 to +700, with the additions of Mikal Bridges and Karl-Anthony Towns. The Knicks have attracted the second-most money from bettors at ESPN BET, behind only the Celtics. Boston hosts the Knicks in the season opener Tuesday.

"Right now, the Celtics and Thunder have taken the most handle, but that is expected by the two teams with the shortest odds," Halvor Egeland, trading manager for BetMGM, said in a company release. "The Knicks are not a great result either."

David Lieberman, who oversees NBA odds for Caesars Sportsbook, said he has been surprised by the amount of support the Knicks have received from bettors, but noted that two West Coast teams pose the biggest liability in their NBA titles futures markets.

"The [Los Angeles] Lakers are typically the worst-case scenario, and that's the case again this year, followed closely by [Golden State] Warriors," Lieberman told ESPN. "With both being popular teams and at relatively high odds, it's not surprising."

The Lakers are 33-1 and Warriors 40-1.

The 76ers' title odds improved in the offseason with the addition of veteran Paul George, moving from +1600 to +825. Those are the shortest preseason title odds the 76ers have had since 1986, according to ESPN Research.

The Brooklyn Nets begin the season among the biggest long shots to win the title at 1,000-1. Caesars Sportsbook reported taking a $750 bet on the Nets to win the title at 1,000-1 odds in June.