So if it ALWAYS moves "away" from a ref. point, then, that is all that is needed as a basis.
One group of people will place a line into the future, forecasting that "when price reaches this point it will bounce because yada yada yada...". What is the point in doing that?
The bottom line is that whatever you try and forecast into the future it does not change anything. Price will go where price wants to go, it will go above or below any line you place on your chart anyway, so it is pointless to anticipate a move.
Gauging which way it flows 'from your line' and the intensity/conviction with which it moves is another story all together...entry.
And of course, lets not forget that at any given moment, price will move unexpectedly, hence an outcome from a given scenario will transform itself into multiple/different outcomes...trade management/exit.
Argh, it is in my head but i just cannot explain it, its like a big bowl of spagetti thoughts right now.
Reminds me of the controversial Random Coin Toss (http://www.npr.org/templates/story/story.php?storyId=1697475) (heads or tails):
"Each human-generated flip has a different height and speed, and is caught at a different angle, giving different outcomes."