The over-under for Jackson's rushing total for the 2020 regular season opened at 999.5 yards at Caesars Sportsbook.
Jackson rushed for 1,206 yards in 2019 -- a single-season record for a quarterback -- en route to being named NFL MVP. However, each of the previous three quarterbacks to rush for more than 900 yards in a season recorded less than 600 rushing yards the following year.
Jackson said last week that it didn't matter how much he ran the ball, as long as it helped the Ravens win. He also predicted he wouldn't put up the same rushing numbers in 2020.
"I doubt that I am going to be carrying the ball a lot going further into the future, because we have dynamic running backs and even more receivers," Jackson said. "We are going to be pretty good, and I don't think I'll be running a lot."
Jackson had similar expectations heading into last season, saying he thought he would run the ball less before ultimately breaking Michael Vick's single-season record. He has repeatedly talked about how he enjoys passing the ball and famously said "not bad for a running back" after throwing five touchdown passes in last season's opener.
One of the most dynamic runners in the game, Jackson spun, faked out and ran past defenders to finish last season as the NFL's sixth-leading rusher, which surpassed Vegas' expectations. Jackson's preseason rushing over-under at Caesars opened at 867.5 yards, which he surpassed in Week 12.
For dual-threat quarterbacks, posting big back-to-back rushing seasons has proven elusive. Randall Cunningham ran for 942 yards in 1990 but managed just 549 the next season. Vick rushed for 902 yards in 2004 but was limited to 597 the following year. After Vick established the quarterback rushing record in 2006 with 1,039 yards, he didn't play the following season after being convicted on dogfighting charges.
This year, the other prop bet for Jackson is his passing over-under, which opened at 3,199.5 yards; he passed for 3,127 last season. If Jackson goes over on both prop bets, he would become the first player in league history with 3,200 yards passing and 1,000 rushing yards in a season.
ESPN's Ben Fawkes contributed to this report.