For me, technical analysis could be regarded as a tool for your reference only. You also need to take into the consideration of all other factors. Of course, it could not provide you the exact picture of what is
going to happen in the future. However, it could give you some hints, of course not always, that what is
likely to happen in the future.
Reading the charts and the graphs could give you more chance to win the game. For example, if you understand the concept of Relative Strength Index (RSI), is it really that you need to sell your stock if it reach over 80 and buy again only at RSI=20. My experience tell me that this doesn't work. A stock could have further increase even if RSI=90 (e.g. 941, in October and November 06) and could drop further if RSI=20 (e.g. 606, recent performance).
The game is not so simple. The RSI should be read together with other data.
To conclude, technical analysis is a reference only. Don't solely rely on that and enter the game.