Well yeah, that's pretty much what this thread is intended for

It goes like this:
Everybody who enters this thread starts with 1000 points.
Anybody can post a problem they're not motivated to solve. This should include a short description, an estimation of how many hours of pure work (counted without breaks) the task will need, and, if applicable, the deadline.
The post's time and date are the starting time.
The players now can place any amount of their points as a bet, namely "I bet xyz will NOT have finished their task by date/time".
Once the task is finished, the time specified in the bet compared to the time actually needed determines how many points the bettors get back:
time - points awarded
00-10 % - 100 %
10-20 % - 110 %
20-30 % - 120 %
30-40 % - 140 %
40-50 % - 160 %
50-60 % - 180 %
60-70 % - 200 %
70-80 % - 250 %
80-90 % - 300 %
90-100% - 400 %
>100% - nothing. They did it. You lost those points.
The person performing the task will be awarded all lost points!
As an example: The task was estimated to need 6 hours of pure work. The bets were: A - 1h; 500 poitns, B - 10h, 50 points, C - 11h, 100 points. After 10h, it's finished. A just gets their points back, that guess was too careful. B was spot on and gets 200; C gets nothing.
C's 100 points go to the person who did the task.
Of course, this sytem isn't very balanced and relies a lot on everybody playing fair (especially giving a fair estimation on how long they will need as well as only posting "done!" when it's actually finished), but I'm sure you guys can be trusted in this respect

I'll give my best to keep track of the points in this post. Any amount of bets can be active at the same time.
Let's determine the winner by the end of this year! \o/
*really wondering if this can possibly work*