tektek.org avatar contests get about 7,000 to 12,000 entries per contest. For every avatar to be considered fairly, each entry must get about the same amount of total views and the avatars that raters see must be random (so people with lots of friends can't mass-vote for each other)
This means that you probably won't ever see avatars you've made. When you vote, two avatar submissions with the lowest total amount of views are selected at random. Then, based on your choice, one of three things happen:
This process continues as long as you want to keep rating avatars. When the contest is marked as ended, the avatars with the highest scores win.