Hi,
I agree with you that there is certainly a subtle difference in the tests that are more recent (less formulaic logic in LR, the reappearance of unusual game types in LG, and more subtly-worded answer choice options in RC), and that as a result your study focus should be primarily on those tests. And while you do have to take your score with a bit of a grain of salt when doing a PT you've completed previously (hold yourself to a higher standard), there is value in retaking those PTs, including cementing good habits and noticing modern trends that make certain answers correct or incorrect. So I would encourage you to keep on a practice test schedule that incorporates even the more recent tests that you've taken previously (preferably ones that you took a longer time ago). Plan to retake anything from PT 72 and beyond. It will be good practice. Make sure you also schedule in the practice tests in the 80s that you haven't completed yet.
Given that you're already in the low 170's, there won't be as much remedial work to do (brushing up on individual question types, game types, etc.). So with every PT you complete, you have to really run the review process into the ground, focusing most obviously on questions you missed but also making sure you identify and review any questions where you had even a little bit of doubt about the answer choice you selected. Allow yourself more time than you think you need for the review process (I usually find people are too hasty about moving on from a PT), and use that time to both understand the questions you've missed or were uncertain on, and also to identify the most efficient way of identifying the correct answers on those questions.
Finally, consider whether a tutor could help you identify some targeted areas that continue to be problematic for you and shape some study drills in addition to practice tests that could help shore those problems up. We'd be happy to discuss options with you if that's something you'd like to explore (more info here:
https://www.powerscore.com/lsat/tutoring/)!
Best of luck as you continue on in the study process, and let us know if there's anything else we can do to help!
Jeremy
Jeremy Press
LSAT Instructor and law school admissions consultant
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