Gulfstream Park's Rainbow Pick 6 on Sunday is a mandatory payout and is expected to have a pool of more than $5 million, providing the potential for a huge score. The six-race sequence begins with Race 6 at 3:23 p.m. ET and ends with Race 11. Before you make any picks, you NEED to know how racing insider and accomplished horseplayer Bob Weir has handicapped the six-race sequence.

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. 

And this year, his first for SportsLine, Weir has been on fire. In January he crushed the Pegasus World Cup, giving out an $8 exacta and a $1 trifecta, winning $757.60. In February's Sam F. Davis Stakes, he gave out the $.50 superfecta, which paid $150.75. Last month Weir correctly pegged Wells Bayou to win the Louisiana Derby.

And he nailed the late Pick 4 at Gulfstream Park on both April 9 and April 10, hitting for $827.65 and $394.65, respectively. Anyone who has followed Weir this year is WAY UP.

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

We can tell you that Weir is high on Makisupa, an 8-1 longshot in Race 11, the final leg of the Rainbow Pick 6. This 3-year-old filly finished fifth in her first career start, on March 8, for trainer David Fawkes, who excels with second-time starters, winning at 24 percent. "Any improvement gives her a solid chance," Weir told SportsLine. He has designated Makisupa as an "A" horse on his Rainbow Pick 6 tickets.

In addition, Weir is high on a double-digit longshot on Sunday! This horse ran against the pace bias in her last start, but "if there is a reasonable pace, expect an improved performance," Weir told SportsLine. This horse could light up the tote board and spice up the Rainbow Pick 6. Weir is including this longshot as an "A" horse on his tickets, and so should you. You NEED to see Weir's analysis before making any Rainbow Pick 6 selections.

Weir also is including a bonus pick for Race 10. "I have been waiting a month for this horse to run back," Weir told SportsLine. He has exactas involving this horse that you need to see.

So which double-digit longshot can win at a HUGE price? How has Weir constructed his Rainbow Pick 6 tickets? And what horse has Weir been waiting a month to bet? ... Join SportsLine now to get Rainbow Pick 6 selections at Gulfstream Park for Sunday, all from the racing insider who hit the Pick 4 on April 9 and April 10!