What is a Quadrella?
A Quadrella (or 'Quaddie') is a type of exotic horse racing or greyhound bet. The bettor must pick the winner of a given set of four races. The greater the number of runners the bettor selects, the more the bet will cost. In horse racing the Quadrella is usually the last four races of a given event, whereas in greyhound racing this is usually races 5 to 8.