A competition scheme could be based on expectancy which is for forecasters to classify/provide "Strong Up, "Up", "Down" and "Strong Down" predictions, rather than numbers. Strong means 2 points, and is perhaps defined according to last year's statistics.
Guessing right will get 1 point for "UP or Down" or 2 points for "Strong", depending on her/his projection weekly. Guessing wrong will loss 1 or 2 points, depending on where the ES ends each week.
Comes down to interest really which is about money west of the Atlantic. Oh and of course bragging rights. I see OT has suggested his system to a T2W thread.
Why not host it OT on ET and see if there is any interest ? Of course prizes would help.