You simply can't "grill everybody hard" just to test for their success. The goal just can't be to knock out "luck" totally. The problem space is just too big to

You simply can't "grill everybody hard" just to test for their success. The goal just can't be to knock out "luck" totally. The problem space is just too big to handle. If you can throw out 50 people out of 100 who are very likely (let's say 90%) to not include the one you are looking for, then your chances to find the one increased from 1% to 2.25%, which is more then double your chance with 100 people and also a lot less work.