He found the most important opinions, at least judged by how many times they were cited, by working out which nodes were likeliest to fall on the shortest paths between two other nodes. Intriguingly, the cases mostly come from an advanced and esoteric subject—the law of federal jurisdiction—that addresses structural features of American government, such as the relationship between the states and the federal government and the relationship between the courts and Congress.
But the federal jurisdiction cases "are not ... the cases that are most tightly bound into the network":
To find the network's so-called main core, Mr Chandler repeatedly filtered out less-connected cases. He found that most of the cases in the main core interpret the American constitution's First Amendment, which protects freedom of speech and free exercise of religion. This, he suggests, means that deciding a free-speech case requires understanding a more complex body of precedents than deciding any other kind of case. By the same token, any First Amendment decision, right or wrong, will reverberate more readily through the law than a decision made in any other area.