Goodreads currently boasts around 75 million members, and around 10% to 20% of all my readers rate my books there. In fact for a swath of recent traditionally published fantasy there seems to be a strong correlation between number of sales and number of Goodreads ratings.
Many awards are accused of being a popularity contest, though generally they are just a popularity contest among a small clique of fans. The Goodreads Choice Awards, with 3.8 million votes cast last year, really are a popularity contest. How well a book has sold has a very strong bearing on how well they will rank.
With this in mind I looked at all the results since the awards started in 2010 and plotted the breakdown between male and female authors.
(click for detail)
Now extended to the 15 nominees for 2018.
The results indicate that in the very popular genres of Young Adult Science Fiction & Fantasy and Paranormal Fantasy female authors have dominated in these awards (and by extension, in sales), averaging 84% & 87% of the top 15 respectively.
In the first 4 years of the awards female authors averaged 45% of the top 15 in the Fantasy category. In the second 4 years after the joining of the Fantasy and Paranormal Fantasy categories female authors averaged 63% of the top 15 in the combined category.
Only in the Science Fiction category does there seem to be a consistent majority of male authors, with an average of 28% female authors in the top 15.
Science Fiction does still seem to be a bit of a boy's club and it's unclear from the data whether that is changing.
If there were sufficient numbers of books involved we could look into "Fantasy" and break it down into various sub genres, and I'm sure would find some where one gender was having the majority of success and others where the situation reversed.
It is interesting to note that even after the combination of Fantasy with Paranormal Fantasy there are still more votes (interest/sales) in the YA SFF category (and fewer in the Science Fiction category), except for years when JK Rowling has her hat in the Fantasy ring (and she has a huge YA following).
It is of course dangerous to draw too many conclusions from such analysis, so I merely present the data. And clearly it is scant comfort to know your gender are doing great in one area of writing if the books you write fall into an area where you feel you're swimming against the tide.