These are two very, very different questions.
1. PhD – Will vary depending on the program. For most programs, as I am informed by our PhD admissions Team (to clarify, these are members of our team who are working on or have a PhD), the biggest factors are: A) your recommendations – who they are from (i.e., professors in the field) and what they say, and B) Your serious scholarly/academic work to date.
Obviously, letters from more well-established professors proclaiming you as the next great academic will go farther than a luke-warm letter from someone who just started as a professor.
Similarly, if you are published pre-application to PhD programs (or have worked on serious scholarly work), your chances are great.
2. MBA program – I suggest you reach out to Ellen Skinner (who runs the MBA program at InGenius Prep). The short (and frankly, incomplete) answer is that these schools are looking for people who have hit some threshold test score/GPA (conventional wisdom is 700 for top schools), who have demonstrated leadership experience/skills, and who offer something unique to the make-up/composition of the incoming class.
This is obviously nothing new. What I would emphasize is that test scores (and definitely undergraduate or post-grad grades) are truly threshold matters – we’ve helped numerous students with GMAT scores under 700 get into some of the best programs. How much and to what extent these things matter will depend on the rest of your application.
If you have little or no post-graduate experience (work or otherwise), these thing will matter much more. Generally, it is the ”soft-factors” (i.e., not grades, test scores, etc.) that matter most in MBA admissions.
Hope that’s helpful. Here is an article which you might find helpful as well: MBA Rankings: Friend or Foe