It was two years ago today...

[mickeycrimm]

A few pages back in this thread I asked Alan to ask the craps dealers how many combinations add to 10 when you are rolling three dice. Alan quickly wrote it off as "bullshit questions about three dice." As Alan has said, a die has six sides. But the fact that it has six sides has led some people to draw some wrong conclusions about dice. The question of how many combinations add to 10 when you roll three dice played a roll in the history of the study of the probabilities of dice throws. It's the story about the dice gambler and the dice hustler.

In very early 17th century Italy a dice gambler got introduced to a new gambling game played with three dice. I call the person that introduced him to the game the "dice hustler." It didn't matter who rolled the dice. They were betting on totals. And the only two totals that mattered were the nine and ten. All other outcomes were no action.

The dice gambler bet the nine and the dice hustler bet the ten. When the total added to nine the hustler paid the gambler. When the total added to ten the gambler paid the hustler. The dice gambler had streaks where he did pretty good....but over time he was slowly but surely losing all his money to the dice hustler. He couldn't figure it out. He thought he had the best number. He thought he should be winning. After all, the dice are six sided....three times six is eighteen....half of eighteen is nine....that's the mean number....it should be the best number to have. But he kept losing and losing and losing.

Finally he had had enough. He quit the game. But he still wanted to know why he lost. He had a friend, a noted scientist and mathematician by the name of Galileo. He took the problem to Galileo.

Galileo studied the dice and the game for a couple of days then gave his friend an answer. He told his friend that there were 216 total combinations with three dice (6X6X6). Twenty-seven of those combinations added to 10, but only twenty-five combinations added to 9.

Because of this event Galileo was credited with being the first scientist/mathematican to work out the probabilities of dice throws. But you can bet your ass the dice hustler knew the reason the dice gambler was losing long before Galileo did.