I will have to disagree on this one. Shelf and board scores may measure medical knowledge, but that is only one component of competence. Being a good physician involves much more, including clinical performance (i.e. data gathering, interpreting lab data, sythesizing all of this info to formulate an assessment and plan,), professionalism (getting along well with residents, attendings, nurses, patients, etc...), and also work ethic (staying on top of your patients and working hard to make sure things get done for them in a timely manner). You cannot measure this stuff on the shelf exams. I've worked with residents who had great Step 1 and 2 scores, but who were also lazy, had poor judgement, and had no clue what was going on with their patients. Doesn't that strike you as incompetent? A hybrid of shelf exam scores and clinical evaluations is the only way we have to assess what kind of resident a medical student will turn out to be.