Hi JF,
Thanks for the question! I'll directly answer your question in a moment, but first a note for other readers of this thread: that advice is made with a caveat based on the amount of time you have. If you only have, say, 4 weeks to prepare for the LSAT, you would want to start with more recent LSAT games.
Ok, that aside, the general theory here is that as your actual test date approaches you want to study the most recent LSATs that have been released. This is because the belief is that the most recent tests will feature the ideas they are currently emphasizing when making the LSAT. For example, recent LSAT LG sections feature the occasional Rule Substitution question, whereas that question type didn't exist 10 years ago.
This isn't to say that only recent LSATs are useful—far from it. Logic is logic, and it's not like the principles of logic have changed
If you want to read more about the usefulness of older LSATs, check out my blog post on the topic:
http://blog.powerscore.com/lsat/bid/282 ... lder-LSATs.
One benefit of studying the older LSATs first is that you get a more structured look at how the LSAT has changed. There have been subtle changes over the years in the language used by the test makers, the types of questions emphasized, and the types of rules and reasoning most featured. When you look at the LSATs that are older first, and then move towards the newer LSATs, you can more clearly see these shifts, which better prepares you for how the LSAT is given today.
This is actually a topic I could probably go on about for quite a while, but I don't want to bore you (well, not any more than I already have
) so hopefully this gives you a basic sense of the reasoning behind this approach.
Please let me know if that helps. Thanks!