I am also agree withyou as there is no strategy that could give us 100% surity, as each indicator and strategy gives us the signal about the past data, does not tell us the current situation, I think if we want to get 100% surity then we must learn fundamental analysis i havelooked and i have searched but i haven't found even professionals who trade millions of dollars donot have such a strategy . if you strategy can return between 50-70% i think you have a winning strategy and you should keep it