butch@inuxc.UUCP (R Meese) (01/14/84)
There has been a few questions about backgammon reading material
and programs lately. I like to answer your questions but
do not have the time right now. I have a list of books both
for the beginner and any one else wanting to improve there
game. I would like to see how many backgammon people there
is and with enough maybe some one can start "net.games.bg".
Until I can get the list together - here is a backgammon problem.
Backgammon problem - X doubles to 2?
24 23 22 21 20 19 18 17 16 15 14 13
'O' off |===========================================| 'O' PC=18
O O O || O O O | | ||
O O O || O O O | | ||
|| O O O | | ||
|| | | ||
17 Point Match || | | ||
X-8 O-5 || |BAR| || cube@ 1
X dbl to 2? || | | ||
|| | | ||
X X || X | | ||
X X X || X X | | ||
X X X || X X X X | | ||
'X' off |===========================================| 'X' PC=27
1 2 3 4 5 6 7 8 9 10 11 12
In this problem, the number of rolls to bear-off the remaining
pieces is more important than pip count. 'X' is behind in
pip count 27 to 18, but may be favored to win because of the
number of rolls needed to bear-off and being "on-roll"(X's
turn to roll).
There is no equation to calculate the average number of rolls
needed to bear-off a set position. Looking at both sides of the
of the board, you can estimate the number of rolls. 'X' has
7 pieces left and will bear-off in 4 rolls if he misses once and
5 rolls if misses twice without doubles and with doubles maybe
2 or 3 rolls. 'O' has 9 pieces left and can bear-off in 3 rolls
with 2 sets of doubles, 4 rolls with 1 set of doubles and
5 rolls without any doubles.
One method to determine X's chances to win is to play the position
a number of times. This position was played out 100 times
producing 73 to 27 games for 'X'. At 73%, 'X' has a double
and 'O' has a marginal take since the score in the match does
not come into play here.
These precentages are based on the fact 'X' was on-roll and
if 'O' was on-roll, 'O' would probably be favored.
Be glad to answer any questions about "BG", just mail them to
me.
|:~) inuxc!butch