I don't think you can say applicant B is more qualified than applicant A for a lot of reasons other than just stats. However, if we're speaking in terms of stats, you have to consider that the MCAT is a one day assessment of your ability to think through material that is presented that day. Each test is different and depending which form you get may affect what scaled score you receive. For example, when I was taking my mocks my scores ranged from as low as 30 to as high as 41. On the real deal, I scored somewhere in between, but I could've just as easily scored a 30 if I had gotten a "bad" form for me and by your definition, a person with a 33 would have had a better grasp on the basic science. Or on the flip side, I could've scored a 41 and said that I have one of the best grasps on basic science and critical thinking than anyone applying to medical school, which wouldn't have been necessarily accurate either; I could've just gotten a form that was tailored to my strengths. The point is the difference between say a 30 and 33 can be only a handful of questions, and I think the questions one is asked on a given sitting can have a large effect on their overall score. AAMC likes to believe there isn't this kind of fluctuation on the tests, but I'm sure many of you can attest, your practice scores can be somewhat bipolar at times as were mine. In addition to MCAT discrepancies, grades are subject to this kind of bias as well. The person with a 3.7 could've taken an easy major at an easier institution and done relatively well and the person with a 3.3 could've had a hard major etc. You get the idea. Thus, I think both grades and the MCAT can be subjective and the truth as to which is a better indicator probably lies somewhere in between the two. They both have their pros and cons, and I think using the combination of the two helps balance these factors. And since grades and mcat scores are used to screen applicants, just do well on both and save yourself and adcoms the trouble of deciding whether or not you're qualified enough for their school. edit: sorry about the block of text, my work computer is acting up.