Does anyone know why so many super high ANACs grades have suddenly arrived? There seems to be plenty when once upon a time there were none.
My guess is two things:
1) As more coins come through, each series develops its own reputations for grading. Things that initially may have been seen as detrimental to grade - poor plating, poor die strike, nicks in certain areas - are now accepted as "common" to a series, and thus are not causing as much of a hit to the overall score
2) Graders are human and have their own opinions. Typically coins will pass multiple graders with each their own notes. At the end there may be more of a consensus for a higher grade than not, and they may choose to award the higher grades in general.
Oh, and finally, more recent higher grades will tend to make people with older coins re-look at them and re-submit them to chase a higher grade. Win-win for the grading company, more business, more profit.
Remember folks, it's a business at the end of the day. Higher graded coins will spur higher prices, and higher market volume. Everyone and their brother will then want their coins graded to try to get the best grade, and the best resale.