 It was coined in America in the early 1900s from horse racing. At the time, at race meets, a large board would display the odds of horses, and the odds were listed for a horse to win, place, or show, which was to make third. And if a punter placed a bet across the board, he put an equal amount of money on a horse to finish first, second, or third. So it was an across-the-board bet that applied to everything, every option.