There are "pari-mutual" betting systems, for instance the system used for horse racing in New York State, which are very market-like by design. Instead of an o

There are "pari-mutual" betting systems, for instance the system used for horse racing in New York State, which are very market-like by design. Instead of an oddsmaker as in the European or Vegas systems, the odds on a particular outcome (e.g. a particular horse to win/place/show) are determined by market activity: the weight of bets on that horse vs. others in that race. http://thefinalwager.co/2015/04/28/horse-racing-parimutuel-wagering/ http://thefinalwager.co/2015/04/28/horse-racing-parimutuel-w... If you are honestly better at judging the ability of particular horses and jockeys to win races than the average market participant, it is possible (at least in theory, I don't know how many people do it in practice) to make money. However, the house "takeout" is pretty high; most places are 15+% on straight bets and can be more than 20% on exotic bets (Exactas, Quinellas, etc.). If not for the high takeout, it would be a very nice system for the bettor. The only time I've ever made money at a horse track was a time when I went with a friend who rode and owned horses, and we spent the entire day in the paddock area (not even watching the races), watching the horses and jockeys come in. She pointed out particular instances where she thought the favorite didn't seem likely to win, and in those cases I'd put down straight bets on the next-best favorite horses, essentially "shorting" the favorite. It worked pretty well, enough to get around the house takeout and almost offset the drinks we consumed in the process. Not exactly something you'd want in your 401k, but not a bad way to spend an afternoon.