Betting on Kyle Larson's attempt at the Memorial Day Double? Read your house rules closely

Kyle Larson will attempt to become just the second driver to ever complete all 1,100 miles of the Memorial Day Double, racing in the Indianapolis 500 in the early afternoon, then flying to Charlotte to run NASCAR’s Coca-Cola 600.

Finishing all 1,100 miles an incredible feat of endurance, timing, logistics and, of course, speed, that only Tony Stewart in 2001 pulled off. That year, Stewart finished sixth in the Indy 500, then took third at the Coke 600.

The expectations for Larson’s attempt are much higher.

At BetMGM, Larson is the favorite to win the NASCAR race at +475. He’s also the most-bet IndyCar driver to win the Indianapolis 500 at +675.

But anyone wagering on Larson this weekend at all will want to take a very close look at their house rules as a number of obstacles could limit how much racing Larson actually gets to do in both circuits.

There’s potential rain in the forecast in Indiana on Sunday. And if Larson arrives late to Charlotte — or leaves Indy early — another driver getting behind the wheel of either ride could complicate wagers.

Here’s how FanDuel, DraftKings, BetMGM and ESPN Bet decide whether or not a bet is action or void in these situations.

Spoiler: ESPN Bet has the strictest policy.

FanDuel Sportsbook

• The start of the race is the signal to commence the warm-up lap. If a driver is not on the grid or ready to start from the pit lane when the signal is given we will void all bets on the selection.
• Bets will be settled on the result at the time of the podium presentation regardless of any subsequent disqualifications.
• The race must be run within 72 hours of the scheduled start time for bets to stand.

BetMGM

• Motor Racing events must take place within 72 hours of the original start time or bets will be void.
• All wagers will be settled according to the unofficial results reported immediately after the conclusion of the race by the governing organization. Any changes to the finishing order that occurs based on appeals, penalties or scoring malfunctions after the race has concluded, will not be recognized. If a race is abandoned and no presentation position or official result is declared all bets on that race will be void except for bets on any markets which have been unconditionally determined.
• Match-up Props: If a driver does not take part in the race, then bets on them will be void.
• Match-up Props:
  • A. Wagers are placed on the driver only, not the car or team.
  • B. If the original driver is replaced by another driver after the start of the race the original driver is the driver of record and the wager will be action.

DraftKings Sportsbook

• The race must be completed within one week of the scheduled start time for bets to have action.
• All bets are action unless the driver who was wagered on does not start the race.
• Match-up Props: Both drivers must start the session for bets to have action. For race settlement if a driver fails to complete the race, the other driver in the match-up wager will be declared the winner. If both drivers fail to complete the race, the number of full laps completed will determine the winner. If both drivers fail to complete the race on the same lap, the official placing assigned by the league’s governing body will be used for settlement. For all other sessions the official placing assigned by the league’s governing body at the end of the stated session will be used for settlement.
• Winning Manufacturer/Team: All bets are action regardless of certain drivers not starting the race.
• Not/To Be Classified: In the event a driver does not start, all bets will be cancelled.

ESPN Bet

• For settlement purposes, a driver/rider who has taken part in an officially-sanctioned practice or qualification session is considered to have taken part in the event, regardless of his eventual participation in the actual race.
• In “Head to Head” bets all listed participants must take part in the session to which the bet refers to for bets to stand, irrespective of whether a driver manages to get an official time.
• In “Outright” or “Place” bets, no refunds will apply on those participants who do not take part for any reason, for the session/event/championship to which the offer refers to.
• All bets which make reference to teams’ performances will stand regardless of any driver/rider changes.