<p>Well, in high school, for the most part, grades are pretty standard. Course work is pretty standard. Sure, there's some deviation, but you can figure out who took which APs, toss out anyone who hasn't taken the honours track, and then look at grades. There is a very objective basis of comparision.</p>
<p>Furthermore, in undergrad admissions, you have some idea of how the kids are going to perform in college. You know if they've gotten good grades in math and want to be math majors, they will probably be successful. The SAT tests some reasoning, but is not the best yardstick out there.</p>
<p>Now, compare an MIT engineer with a Slippery Rock sociology major, based on grades alone. The standardized test becomes much, much more important. If the MIT grad has a 3.2 and a 174 LSAT, while the Slippery Rock grad has a 3.4 and a 160 LSAT, you can probably guess who will be the better student. Hence the greater weight.</p>
<p>The LSAT is scaled in a very odd manner. 120-180, 151 is the median. 170 is the 99th percentile cut-off. I think 174 is about a 99.4%. 158 = 76th percent. </p>
<p>So about half of the LSAT takers are clustered between 144 and 158. One percent are spread from 170 to 180. You can see that there actually are such things as good LSAT scores. </p>
<p>There are a lot of people out there running around with A averages and 1500+ SATs. There are not so many people running about with A averages and 175+ LSATs. My bet is that you can fill the top 20 schools, easy, with valedictorians in high school who have at least a 1400. Law school is a different game. </p>
<p>At least with med school, everyone has taken organic chem, general chem, bio, and physics. You can compare those grades to compare applicants.</p>
<p>The LSAT is not a pancea, however; many schools want to see good grades, as the LSAT is a 3.5 hour exam and the GPA represents four years of work.</p>