Santa Anita Park's Rainbow Pick 6 features a mandatory payout on Sunday and is expected to have a pool of $4 million, providing the potential for a HUGE score. The six-race sequence begins with Race 4 at 5:43 p.m. ET and ends with Race 9. Before you make any picks, you NEED to see the picks from racing insider and accomplished horseplayer Bob Weir.

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 has hit the exacta in the Sam F. Davis Stakes and Tampa Bay Derby and the trifecta in the Risen Star Stakes and Blue Grass Stakes, with the Tampa Bay Derby score returning $1,414. Those are just some of his scores in 2021.

Anyone who has followed Weir is way up.

Now, Weir has handicapped the Rainbow Pick 6 at Santa Anita Park for Sunday, made his picks and constructed his tickets.

We can tell you that Weir is high on Studly Perfection, a 3-1 shot in Race 8, the fifth leg of the sequence. "He should be winging on the front end," Weir says. "Big shot." Studly Perfection is Weir's top pick in Race 8 and a single A horse on his Pick 6 tickets.

In addition, Weir's top pick in one of the races is a big double-digit long shot. Weir says this horse "can surprise" and could spice up the Rainbow Pick 6. You NEED to see Weir's analysis and ticket construction before making any Rainbow Pick 6 picks!

What Rainbow Pick 6 picks should you make for a huge payday? Which double-digit long shot is a must-back? And how has Weir constructed his tickets?... Join SportsLine now to get Rainbow Pick 6 selections at Santa Anita Park for Sunday, all from the racing insider who has been on fire!