Why not Yale

I think the reason that Yale does not have the same level as visibility here as schools such as HBS and Penn has less to do with the class size and much more to do with the general reputation of the school. Yale is firmly in the elite cluster along with schools such as Cornell and Berkeley while the HBS and Penn are firmly in the ultra elite cluster. Yale SOM does have a number of strengths but is generally outmatched by the ultra elites. Further, it is important to note that Yale is a very young business school. Considering the fact that many of its rivals had a head start of nearly 80 years Yale has actually done quite well. In the long run it would not be surprising to see its visibility rise as the school matures.

Your undergraduate record is usually more important than the graduate level record since virtually all applicants have undergraduate records and thus it can serve as a point of comparison.