I am intrigued as to how crosswords are rated with reference to levels of difficulty.

My two most recent crosswords are currently shown as follows:

Simply General Knowledge (56) 'Harder'
Simply General Knowledge (57) 'Average'

I'm only able to relate to the scores shown for Gold Members, where (56) currently indicates 75% completed in Difficult mode whilst for (57) it's just 26% in Difficult mode. On these figures alone it appears the ratings don't make a lot of sense, unless of course the scores for non-Gold members are the opposite and assuming they are taken into consideration?

Can somebody perhaps explain the apparent anomaly?

Have I perhaps posted this question on the wrong boards, or is the answer simply unknown?

Well, as a crossword editor I can say that I definitely don't know the answer. Terry might be able to say, but I don't know that he can.

(The reason I didn't "answer" before is that I don't usually when all I can say is "I don't know" )

It occurred to me on looking at this question again that it may be related to a statistic that is not shown, such as the number of players who started it but never completed it at all. (Just as quiz player ratings can dramatically affected by the average, poor and very poor ratings which are not displayed in the summary, if there were a lot of players who simply gave up, a crossword might be considered more difficult?)

Many thanks spanishliz and looney tunes for your replies. Whilst the subject is of no substantial significance, I find these classifications 'intriguing' to say the least!