Be imprecise. Understand the concept of “by-and-large” and use approximations. Because our educational system is hung up on precision, the art of being good at approximations is insufficiently valued. This impedes conceptual thinking. For example, when asked to multiply 38 by 12, most people do it the slow and hard way rather than simply rounding 38 up to 40, rounding 12 down to 10, and quickly determining that the answer is about 400. Look at the ice cream shop example and imagine the value of quickly seeing the approximate relationships between the dots versus taking the time to see all the edges precisely. It would be silly to spend time doing that, yet that’s exactly what most people do. “By-and-large” is the level at which you need to understand most things in order to make effective decisions. Whenever a big-picture “by-and-large” statement is made and someone replies “Not always,” my instinctual reaction is that we are probably about to dive into the weeds—i.e., into a discussion of the exceptions rather than the rule, and in the process we will lose sight of the rule. To help people at Bridgewater avoid this time waster, one of our just-out-of-college associates coined a saying I often repeat: “When you ask someone whether something is true and they tell you that it’s not totally true, it’s probably by-and-large true.”Remember the 80/20 Rule and know what the key 20 percent is. The 80/20 Rule states that you get 80 percent of the value out of something from 20 percent of the information or effort. (It’s also true that you’re likely to exert 80 percent of your effort getting the final 20 percent of value.) Understanding this rule saves you from getting bogged down in unnecessary detail once you’ve gotten most of the learning you need to make a good decision.
