Nineteen three-year-old horses will leave the starting gate in the 2021 Kentucky Derby on Saturday, May 1, at Churchill Downs. The Brad Cox-trained Essential Quality is the 2-1 morning-line favorite in the 2021 Kentucky Derby odds. Post time for the 147th Run for the Roses is 6:57 p.m. ET.

Before you make any Kentucky Derby 2021 picks, you NEED to see what racing insider Bob Weir has to say.

Based in Saratoga Springs, N.Y., Weir has been handicapping and following horse racing since reading Andy Beyer's landmark handicapping book "Picking Winners" in the late 1980s. Weir is highly invested in the Beyer Speed Figure, a number assigned to every race run by a horse that measures how fast the horse ran. He uses the figure as the backbone of his handicapping. In fact, thanks to his proficiency with speed figures and top-tier handicapping, he landed one of just eight spots on Beyer's figure-making team in 2017, a position he holds to this day.

Weir's methodology has produced multiple five-figure days. In 2014, he hit a $60,000 Pick 6 at Del Mar. The following year, he nailed a $31,000 Pick 6 at Gulfstream Park. In 2016 and 2017, Weir qualified for the prestigious National Horseplayers Championship in Las Vegas!

Last year, his first for SportsLine, Weir was on fire. In June, Weir hit a $2 superfecta in the Ogden Phipps Stakes that paid a whopping $1,039. He crushed the exacta and trifecta in the Forego Stakes in August for $1,134.50. He hit the late Pick 4 at Belmont Park on June 18, June 19, June 25, July 2 and July 5, with the June 25 score returning a whopping $2,159.50.

And this year, he hit the exacta in the Sam F. Davis Stakes and Tampa Bay Derby! He also nailed the trifecta in the Risen Star Stakes and Blue Grass Stakes! Those are just some of his scores in 2021.

Anyone who has followed Weir is WAY UP. Now, he has handicapped the 2021 Kentucky Derby horses, made his picks and constructed his bets. 

One shocker: Weir is fading Essential Quality, even though he is a perfect 5-for-5 in his career and the clear-cut favorite! "He's far from a sure thing and does not hold a clear advantage on this field," Weir told SportsLine.

Instead, Weir is high on a HUGE double-digit long shot who has been training "extremely well" at Churchill Downs! In fact, Weir says this horse is a "MUST-USE" in your bets and could have been among the favorites. You ABSOLUTELY need to see his picks before locking in any of your own!

Who wins the 2021 Kentucky Derby? And which double-digit long shot is a MUST-BACK?... Join SportsLine right now to get the top 2021 Kentucky Derby picks and bets, all from the racing insider who crushed Derby prep races!