In 2016, rookie Alexander Rossi shocked the world, winning the Indy 500 as an 80-1 long-shot. The nation's premier auto racing betting expert, SportsLine's Micah Roberts, was all over Rossi.

Last year, sportsbooks listed Takuma Sato as a 25-1 long shot. But Roberts liked his speed during practice runs and listed him in the top 10 of his projected leaderboard. The result? Sato stunned the IndyCar world with his first win since 2013 and anybody who backed him saw a massive return.

Now he's locked in on this year's running of the Indianapolis 500 on Sunday at 6 p.m. ET and his projected leaderboard is in. 

This year, Roberts is eyeing Sage Karam at 15-1 as one underdog who will make a surprising run, saying he loved his speed in Practice Run No. 8, when he hit over 224 MPH.

But Roberts has identified an even bigger long shot he believes has a real chance to take the checkered flag. Vegas isn't giving this driver any respect, so this is somebody you can cash in huge on Sunday.

Which drivers should you back and which long shot is going to make a statement in IndyCar's biggest event?... Join SportsLine here to see Micah Roberts' full projected leaderboard for the Indianapolis 500, and see which long shot you should be all over, all from the nation's premier auto racing betting expert!