Think of it this way: Take 20 developers. If you give them a test with 200 difficult problems they would all score about the same. Instead, give them 4 difficu

Think of it this way: Take 20 developers. If you give them a test with 200 difficult problems they would all score about the same. Instead, give them 4 difficult problems in a limited time frame. Now some of them will look much smarter than others. Only hire these candidates. Now you can believe you are part of a very selective group.