Taking the LSAT is a skill set in itself. Like all skill sets, being properly taught puts a person at a distinct advantage. This is why companies like Kaplan and Princeton Review can make guarantee that they will raise your score. They know that, much as teaching a person notes and chords will always make them a better musician, if they teach a person the skill sets needed to succeed on the LSAT, the person will always do better. And yet this distinctive advantage comes either at the price of 1500 dollars for a class, or 100 dollars for a book, which will give you an advantage over someone with no training, but will not give you the leg up that someone who was taught by a professional got.

Far more important than the ability to take an exam is experience. The first area the NAACP went after in the battle against school desegregation was law schools. In cases like Sweatt v. Painter, the NAACP sought to show that a diverse and experienced law school class were essential to a legal education, and simply providing the same material resources and teaching to Mr.Sweatt would not give him the same education as putting him in the classroom with students from across Texas and the nation.
Additionally, working as a paralegal or a legal researcher, or working in an area that the law will effect gives a person a frame of reference when learning a law. Seeing how a decision will be put into practice, gives a person a pragmatic view of a decision.
But this gem of experience, which is becoming more valued, is still secondary to LSATs. Because their is not quantitative measure of experience that is valued as higly as average LSAT scores, experience is diminished at the alter of LSATs.

One of the easiest ways a school can move up the rankings is to raise their average LSAT score. And many schools will say it is all about a good fit and not about the rankings. But, when employers, especially for clerkships, where there are only a few places, are looking at hundreds of applicants, or eve thousands, the quickest way for them to narrow down the field is to eliminate all students that did not go to a top 15 or top 20 or top 50 school. While this undoubtedly eliminates great candidates, it is not possible for a judge, who is already trying to move along his docket, to look at hundreds of applications, so by limiting the law schools he or she can limit the number of applications and a feasible job of picking a clerk. Likewise for a law firm or for government or public interest firms that have too many applicants for summer associate and job openings, and so when looking at recent graduates, they are forced to eliminate great candidates because of time constraints.