Why You Explore First

Say you will see 10 apartments, each only once. View the first 4 and reject them all, even a great one. You are not wasting them — you are building a yardstick for what counts as good. After that, grab the first apartment that beats every one you saw. With no benchmark, you cannot tell a strong option from an average one.

37% sounds modest, but it is close to the best you can do. With 10 options, blind guessing lands the best one only 10% of the time. The 37% figure (1/e) is the limit you approach as the number of options grows large; with just a handful, the odds run a little higher — around 40% for 10 options using exactly the reject-the-first-few strategy above. You can't do much better than that, because you never see the whole set before deciding, so a method that always wins simply does not exist. The rule squeezes out the most information a one-at-a-time process can give you.