==> probability/darts.s <==
Since the three darts are thrown independently,
they each have a 1/3 chance of being the best throw.  As long as the
third dart is not the best throw, it will be worse than the first dart.
Therefore the answer is 2/3.

Ranking the three darts' results from A (best) to C
(worst), there are, a priori, six equiprobable outcomes.

possibility #	1	2	3	4	5	6
1st throw	A	A	B	B	C	C
2nd throw	B	C	A	C	A	B
3rd throw	C	B	C	A	B	A

The information from the first two throws shows us that the first
throw will not be the worst, nor the second throw the best.  Thus
possibilities 3, 5 and 6 are eliminated, leaving three equiprobable
cases, 1, 2 and 4.  Of these, 1 and 2 have the third throw worse than
the first; 4 does not.  Again the answer is 2/3.