Don't smaller programs provide more individualized instruction from faculty in general? Also, most of the 2-3 residents per year I see cover a single hospital when on call -- something that is really great.A big difference can be in call schedule. The fewer the residents, the more frequent the call (most times). Also, if you have multiple hospitals but few residents, things can get stretched out on the services as well. So, you want enough residents to be able to parse out the work so there's time to pursue the electives that you want, but not too many people that you become a....medicine resident in a huge program. This is why I turned down Partners - I didn't want to be 1 of 17 - and that's just for one year's class. But, others like that. So, it really ends up depending on you. For me, the minimum was 4 (per year) and the max was around 8-9, with 6-7 being ideal.