Our new data tool, Tracking Major Rules in the Courts, compiles more up-to-date case results that can be easily compared across presidential administrations, and offers additional research findings. Between 2017 and 2021, the Institute for Policy Integrity[[The Institute for Policy Integrity has filed amicus briefs in several of the cases discussed in this Roundup. Policy Integrity did not represent any of the parties.]]documented the outcomes of litigation over the Trump administration's use of federal agencies to implement its policies.[[The Roundup does not include litigation over self-implementing presidential memoranda or executive orders or over project-level decisions.]] We tracked litigation over agency actions such as regulations, guidance documents, and agency memoranda.[[At times, advocates have brought lawsuits over a single agency action in multiple different courts. The Roundup combines decisions from different courts regarding the same agency action in a single entry. ]] The win-loss rate below reflects all decisions through January 20, 2021, when the Biden administration took office. [[A new administration’s litigation strategy may differ from the previous administration’s litigation strategy due to differences in policy objectives. See Bethany A. Davis Noll, “Tired of Winning”: Judicial Review of Regulatory Policy in the Trump Era, 73 Admin L. Rev. 353, 389 (2021) (noting ways in which Biden administration’s strategy changed in light of substantive goals). Accordingly, changes after President Biden took office are not clearly attributable to the Trump administration, and we did not recategorize reversals that occurred after this transition.]] Any reversals or modifications on appeal that occurred during the remainder of 2021 are noted in the case descriptions. [[The Roundup reflects wins and losses as they stood on January 20, 2021 when President Biden was inaugurated and his administration took over the defense of cases. Subsequent reversals on app