Learn from my...
> Own rushed (2wk) case prep process to get into BCG London
> "Most consistently positive interview feedback" the Senior Partner who called with my job offer had ever seen
> 5+yrs as a 1st & 2nd round interviewer (150+ interviews from interns to experienced hire Principals for the Energy practice)
> Mentoring summer mentorship applicants (with 100% success)
> Years of CV screening for undergraduates / MBAs / experienced hires
From all of the above, I know what it takes to get an offer, that you don't need to drill 50+ cases, and have distilled the key things to focus on to make the process as efficient and enjoyable as possible for you.