In Brazil, as in most other countries I know about, law school is a five year program starting after law school. There is a process here where students are tested in the areas of general knowledge and law when they enter law school. Students in the fifth year are also tested in those areas. The process is designed to determine if the school makes a difference and how much relative to others. This is not done every year for every school nor do I know if there is a national ranking that results but it does occur to me that this is a measure of performance unknown to those who rank US law schools. Maybe the distinction is this. You can rank a law school on the basis of LSAT, GPA, etc but that does not tell much about actual performance. Or you can rank schools on the basis what actually happens during the three years. If performance counts, the before and after approach makes sense.
As a side note, the School at which I have taught is a private school. Admission is based on an entrance exam. Numbers only. (This has changed some as the public colleges have quotas for those from public schools or who are of African-Brazilian descent and there are incentives for private schools to open up admissions more. More on this over on classbias.) The top 180 are accepted. I asked what would happen if that meant all while men. The answer was that it would not matter. I asked what the reality was. Over 50% of the admissions are women.