Before

'Before' shot / from PRS, Vol. 1, No. 2

'After' shot / + $10.52 in 4 1/2 weeks,
+40.49%

That's an $8.51 flag 'pole'. ($20.61 flag pole low, to $29.12 flag pole high, equals an $8.51 'pole'.) Simply add $8.51 to the flag's breakout point (in this case it was approximately $28.12), for your measured move target of $36.63. This one was a near picture perfect example. It reached it's measured target of $36.63 on 12/11/01 (it actually pushed a bit past there to a high of $37.32), before closing at $36.50. After a great run like that, it would have been very easy and rewarding to exit that trade with great satisfaction. 

There are several ways to trade chart patterns. The most common way is to buy (if it's a bullish continuation pattern like this bull flag example), once it breaks out through the top of the pattern. (Descending red line). However, many traders (myself included), can opt for a lower risk entry by getting in as soon as the pattern is identified, in anticipation of an eventual breakout.

I call it a lower risk entry because I'm closer to my stop-out point in case of a pattern failure. In other words, if I were going to exit the trade on a close below the bottom of the pattern, (a pattern failure), I would have a smaller risk of loss getting in nearer the bottom of the pattern as opposed to getting in higher up or nearer the top (or waiting for a upside breakout). Of course, if the pattern were to fail without ever making an upside breakout, I'd have a small loss, whereas the trader waiting for the upside breakout would never have even gotten in, therefore avoiding a loss entirely. But on many patterns, I like getting in as soon as they're spotted in an effort to capture an even larger move with a relatively lower risk entry.