Three backgammon players of equal game skills compete for a prize.
The prize will be awarded to the winner of two games in a row.
A and B, following a drawing, play the first game, then the winner will
Next game, if needed, will be by C and the player who lost the 1st
game and so on.
Determine a priori chances of winning for each of the 3 players, assuming
Lady Luck treats them without discrimination.
Rem: There are no draws in backgammon.