System testing remains a fi ght between computer power and common sense. Before
1980, testing a trading system was a simple concept. Conscientious traders and
analysts applied their ideas to charts, marking the buy and sell signals manually
and keeping a hand-written record of the trades. The process took a long time; therefore,
they were careful not to begin unless they were reasonably sure that the method had a
good chance of success. Ideas came from an understanding of the fundamentals or the
awareness of market patterns, plus valuable experience. The tabulation of profi table results
was verifi cation that the idea was sound.