Man! This is simple English!
The more upvotes and comments you have, the more your chances of winning.
Do we need a professor in English to decipher what that means? The top three communities with the most upvotes and comments weren't even picked, yet you added that sentence I italicized.
Here is a simple rule you should add in case you plan on hosting another contest like this;
Upvotes and comments from community members might be considered.
This is simple enough!
And about visiting the dictionary for the meaning of "chance", I understood it perfectly. You should try to understand it too. Let me quote what you wrote;
The most Upvotes and Comments from bros/members of your community the more chances to win you will have.
Can you please read this again? I know having the most upvotes and comments doesn't guarantee you as the winner. But the top three communities with the most upvotes and communities aren't even in the list of winners. Why include that quoted word then?
Have a good day sir.