Saturday marks the 147th edition of the Run for the Roses, and there is plenty of history that could be made in the 2021 Kentucky Derby at Churchill Downs. Louisville-born trainer Brad Cox will send out Essential Quality and Mandaloun in his first Derby appearance, as he seeks to become the first local trainer to win horse racing's biggest prize. Bob Baffert's Medina Spirit will try to give the trainer a record-breaking seventh Derby victory, while Midnight Bourbon and Super Stock will attempt to earn fellow Hall of Fame trainer Steve Asmussen his first.

Cox's Essential Quality is the 2-1 favorite in the latest 2021 Kentucky Derby odds, while Mandaloun and Baffert's Medina Spirit are both 15-1. Midnight Bourbon (20-1) and Super Stock (30-1) also are long shots to finish at the front of the 19-horse 2021 Kentucky Derby field. The 2021 Kentucky Derby post time is 6:57 p.m. ET. With a talented 19-horse field entering the Churchill Downs starting gate, you'll want to see what racing insider Bob Weir has to say before making any 2021 Kentucky Derby picks.

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. On June 13, 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.

This year, he has dominated the 2021 Kentucky Derby prep races, hitting the exacta in the Sam F. Davis Stakes and Tampa Bay Derby and the trifecta in the Risen Star Stakes and Blue Grass Stakes. Anyone who has followed him is way up.

Now, Weir has handicapped the 2021 Kentucky Derby horses, made his picks and constructed his bets. You can only see them here.

Top 2021 Kentucky Derby predictions

One shocker: Weir is largely fading Essential Quality, even though he is the clear-cut 2-1 favorite. Favorites have won 56 of the 146 previous runnings (38 percent) and came up short the past two years. Weir understands Essential Quality earned his status as favorite, but the racing expert doesn't see where he has proven he deserves such a short number. "He's the most accomplished horse, but I do not see the advantage he possesses that supports taking that short of a price," Weir told SportsLine.

Weir has not been impressed by Essential Quality's speed, with five horses in the field at least equaling his career-best 97 Beyer Speed Figure and six others within five points. He gutted out a victory over Highly Motivated in the Blue Grass Stakes on April 3, but he'll start from the 14th post. No horse has won from that spot since 1961 (Carry Back), and his speed could be an issue if he is pushed wide.

Another curveball: Weir is high on Medina Spirit, even though he's a 15-1 long shot. Baffert has won a record 16 Triple Crown races and swept to Triple Crowns with American Pharoah in 2015 and Justify in 2018. He was expected to saddle the 2021 Kentucky Derby favorite, but Life is Good was injured in March, so the Hall of Famer has focused on preparing the 15-1 shot. "If anyone can get a horse to peak on Derby Day, it's Baffert," Weir told SportsLine.

Medina Spirit also will have a Hall of Famer in the saddle with John Velazquez, who rode Baffert's Authentic to victory last year for the jockey's third Kentucky Derby win. The 49-year-old from Puerto Rico has been racing in the U.S. since 1990 and has won 15 Breeders' Cup races and has two Belmont Stakes victories. Velazquez was on board for Medina Spirit's runner-up finish to Rock Your World in the Santa Anita Derby last month and is likely to be more aggressive this time out.

How to make 2021 Kentucky Derby picks, bets

Weir's win contenders include a 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. He's sharing which horses to back only at SportsLine.

So who wins the Kentucky Derby 2021? And which epic long shot is a must-back? Check out the latest Kentucky Derby odds 2021 below, then visit SportsLine to see Weir's picks for the Kentucky Derby.

2021 Kentucky Derby horses, odds

Program #HorseOdds
1Known Agenda6-1
2Like the King50-1
3Brooklyn Strong50-1
6O Besos20-1
8Medina Spirit15-1
9Hot Rod Charlie8-1
10Midnight Bourbon20-1
11Dynamic One20-1
13Hidden Stash50-1
14Essential Quality2-1
15Rock Your World5-1
16King FurySCR
17Highly Motivated10-1
18Super Stock30-1
19Soup and Sandwich30-1