Then magically in 2019, FanDuel began letting bettors create parlays on the same game and started marketing it like crazy.
If one happens, the other is more likely, so they didn't want you to get the full multiplier value a parlay offers. Many 21st-century sportsbooks never let you parlay two bets from the same game, like a point spread and the over, because those bets could be correlated.