Hi Capt. Corn Pops, I derived that 836 number using a method of calculation that I picked up from a dude that came through here about 6 months ago and shared the technique with the forum whose name escapes me now.
He called it the 'natural ratio' calculation method. Here's how it works:

788-615= 173 pts
788/615= 1.28
173 x 1.28= 221 pts
615 + 221= 836

This calculation technique gives you the minimum target price that the market can hit. Of course the market could go higher than that if the bull continues but the 836 is the minimum target because it is at a natural ratio of the previous high divided by the previous low.