A formula for help
making doubling decisions in pure race situations in backgammon
games. It enhances the basic pip count by accounting for elements of checker distribution. It was devised by Dr. Edward O. Thorp.
Each player's Thorp
count is his pip count, plus 2 for each of his checkers still on the board,
minus 1 for each of his occupied home board points, plus 1 for each checker on
his one-point.
Then the player on roll increases his count by 10 percent if it
is more than 30.
Dr. Thorp advises:
Double any time your count does not exceed the
opponent's by more than 2;
Redouble
any time your count does not exceed opponent's by more than 1;
Accept the double if your count does not exceed doubler's by more than 2.
This Dr.
Thorp is the same who wrote the 1960’s best selling book on Blackjack
“Beat the Dealer” made Blackjack most popular casino game in the U.S.
See post by Simon
Woodhead. For a comparison
with other methods, see article by Tom Keith.