Previous years' question papers play a crucial role in UPSC preparation. They provide insights into the types of questions frequently asked and the marking patterns employed in exams. Analyzing these papers allows candidates to identify important topics and prepare accordingly, enhancing efficiency in study planning. Furthermore, practicing with past papers familiarizes aspirants with the exam format and time constraints, developing their test-taking strategies. Overall, revisiting previous years' papers is an invaluable tool for effective revision.