It's not really a curve at all. It's a straight line. The more complexity you add to your trading -- by looking at more time frames, indicators, currency pairs, systems, at all hours of the day -- the more difficult it becomes to actually implement a profitable trading strategy.
There is a big difference in trading between keeping things simple and being simplistic. Simple means that you specialize in one type of trading, on one time frame, on just a few currency pairs, and that you keep a normal human trading schedule (remember, even Wall Street currency traders work in shift -- no one stays up for 24 hours a day to trade). Simplistic means that you expect to make money without doing any backtesting or homework or planning of any kind (not possible).
