Only The Underdog

I am just wondering but if a sportsbook or a casino only took bets on the true underdog selections (say 50 to 1 outsiders and they only took bets on 1 or 2 out of a total field of 8 or 9). Then would the casino or sportsbook still make a consistant profit? Is there a way of making a consitant safe profit only laying one or two underdogs?

I think that, in theory, they would make the same profit as any sports book. They might not bring in enough business to keep a window open.

Long shot players like to bet favorites too. Rich Riggie once gave 30 to 1 on longsgot horses, instead of the usual 20-1.
He not only wound up broke, but did 2 years in jail.

Ok but what would happen if you gave the correct odds (say you just copied the odds from your local bookmaker or sportsbook) and then continued to lay only one or two underdogs, would you make consistant profit in the long run?