A couple of years ago I taught gambling odds. I could not understand why casino's created a new system for probabilities. Fractions have been around since the Egyptians ( though only 1/n & (n-1)/n were known ), Odds in favor of an event is another way of giving a fractional probability for an event. Why not just use fractions???

I assume casino's want to confuse bettors on odds, to gain more money from players. Hence Odds in Favor of a winner was devised. I expect it is best to stay away from this system of Odds...if you want to win money. Are gamblers familiar with this? Is it a good system? Please share your thoughts.