The pre-clinical years (usually the first two years, but many schools are condensing this phase into 1 or 1.5 years) are very meritocratic in that your standing depends on mostly multiple choice tests. And then you take the first medical licensing exam called Step 1 which largely determines your competitiveness for residency programs. The clinical years where you are actually working in the hospital in various fields is less objective as you are judged based on the subjective feedback evaluations of the residents and attending physicians.

However, you are mostly rated on how much you know, how confident you are and your social skills. So if you did really well in the pre clinical years and are not socially inept then you’ll probably get good evaluations.

But it’s a marathon. It’s an unbelievable amount of information you have to memorize and in the beginning it’s hard to stay motivated when you can’t see it’s direct relevance.

So overall I’d say it’s fairly meritocratic. If you can memorize things well and are social then you’ll do well barring any exceptional circumstances.

From my understanding (2 doctors immediate family and several others extended fam), it can be quite political. Desirable specialties are competitive, whether for lifestyle (dermatology, radiology, etc.) or prestige/interest (things like pediatric surgery). Once you get into a specialty, the work does not stop, as there are usually progressive tiers of training and additional programs. You might do first 4 years residency in Dallas, then receive your next placement in Chicago for 2-3 years. These would be great locations, for most, from what I gather. Most aren’t so lucky.

IIRC the surgery fellowship (8 years after graduating undergrad, 4 years after med school graduation) application process gives a list of 10 cities (hospitals) which the intern is interviewing and applying for. They are allowed to rank their top three cities from this list, but there is no guarantee. They will travel to all ten cities and interview at all the programs.

Medicine is great for someone who wants to be in training until they are mid 30s - and that’s assuming you go directly to med school from undergrad.

My wife recently graduated from a top med school. Her experience was that it was probably 80% "meritocratic" (long hours, grinding it out, being there when someone needs help) and 20% "political" (knowing the right people in the department, knowing what research projects will be good to join and what projects are dogs). To be the top student, you need to know the material well and be productive at research and be a good service provider (good manners, thoughtful, empathetic, etc). The good news is that departments generally give very good opportunities and mentorship to anyone student who shows an aptitude for grinding. Basically, to be in the top 1/5 of the class is all about getting in your reps, and the things that separate the members of the top 1/5 of the class is who they know, who knows them, and the impact and scope of the projects and procedures they were trusted with.