In article ,
Norman Lynagh writes:
As I have said a couple of times recently a single probability forecast
cannot be judged to be either accurate or inaccurate. Accuracy, or
perhaps better described as reliability, can only be judged by
evaluating a representative sample of probability forecasts. I would
think that a minimum of something like 20 forecasts would be needed.

If an event occurred, on average, on 3 occasions out of every 4 in
which it was forecast to have a 75 percent probability of occurrence
then that probability forecasting would have been spot on.

The Met Office forecast of a 2-1 probability of a colder than average
winter cannot, on its own, be evaluated as being either accurate or
inaccurate.

I can't really add anything to that except to say that I agree 100%.
--
John Hall
"Honest criticism is hard to take,
particularly from a relative, a friend,
an acquaintance, or a stranger." Franklin P Jones