I thought it would be funny to post some scenarios to assist those who are chasing that elusive 99. I will post the 3 most important and assume that a 99 image is awesome enough to easily capture 10 or more favorites.

"Wow, I must see this in full size!!!":
This image just has to be seen in full size to get the details that the viewers are so intrigued by and has a 100% download to view ratio. It would require a user rating of 96% in order to achieve the elusive (true) 99.
**FYI: Out of the 13,232 images (and growing) on the site, 8 of them have a 96 rating, and 1 has a 97.**

The Perfect 10:
Every user who saw this image had to bow down to its eliteness. Perfect in every way, this user got a perfect 10 with every photo.
With a mere 92% view to download ratio it could easily capture a real 99 c-index.
**FYI: An image I made that just has to be seen in full size has an astonishing 111 of 128 downloads from views. This is only 86.7%**

I only do just enough to get by:
Assuming c-indexes are rounded instead of the integer taken, it would only require getting a c-index of 98.5 to show a 99. With getting just enough views and downloads, to achieve this a user would need a 9.6 average on votes, and 96% downloads.
**FYI: This should be easy, I'll have one for you in a few days.**