contest task completion rates?

the guys running hang gliding contests are debating their task
completion rates. it looks like 1/3 of pure flex wing entrants make
goal, while 2/3 of rigid wing entrants make goal. sometimes they have
the same tasks, sometimes the rigid wing tasks are a little longer.
sometimes they start at the same time, sometimes they hold back the
rigid wings.

the question is, how do these rates compare to sailplane contests? some
are alleging that sailplane contests plan for 100% completion rates.
true or false? any data?

also, when running a sailplane contest with multiple classes, do you
send the Standard Class out first to mark the thermals for the higher
performance classes, or do you send the Open Class out first on their
own?

Ken
LAK-12
not a racer