Using Decision Rules to Make Better Decisions

From the beginning days of Bridgewater, from your earliest days as a trader, you were writing down. Here are my trade criteria. Here's why I expect this to work. And then that would be eventually reduced to an algorithm? Well, what I discovered, I just did it to reflect on the trade, but I could see how that decision rule would have worked in the past throughout history. That was enlightening. Then I realized that if I could take that rule, that this algorithm, I could also have it process information on a real time basis. As information was coming in, it could go through the rule and then tell me, essentially, buy, sell, and do that.