ALU Chart, page-138

Certain patterns are 75% predictable and the targets they suggest likewise. My analysis is usually about 70% correct but it is impossible to say "the pattern has a target of $10" and expect it to stop spot on that price. It's a matter of watching the psychology of the market (candlestick theory) and knowing when to hold or fold (something that only comes from practical experience). Charting works well in a down market as well as up. Sideways movements are more problematic. If price is range bound and repeated moving between the lower and higher range there may be an opportunity to trade a rise. Sideways actions often result in continuation or reversal patterns (depending on where they occur) and a break up out of a flag or pennant pattern that stopped an uptrend is almost always guaranteed to see a strong rise in price (with a reliable target).
I trade short term (couple of weeks to a couple of months) and try to avoid holding stocks when there price has fallen such that it suggests my original analysis was wrong. Charting is of less value to long term traders or those that back their FA where it suggests the company is onto something and if they kick a goal investors will profit handsomely. Anyone who can do both TA and FA equally well has the best of both worlds - I just find FA too time consuming whereas with TA I don't really even need to know what the company does to trade it.