The adoption of the World Anti-Doping Code (Code) at the beginning of the twenty-first century was a key step towards the harmonization of anti-doping rules at the international level. While the Code provisions have been regularly updated and improved, the basic legal mechanisms chosen by its drafters, including the principle of strict liability, as well as their practical application, continue to generate debate about the standards of fair and impartial adjudication of anti-doping rule violations and the proportionality of sanctions. In 2024, major doping scandals, which forced the public to discuss the shortcomings of the anti-doping system, have affected the tennis with the doping cases of Jannik Sinner and Iga Swiatek, the first-ranked players in men’s and women’s international professional tennis tours. As a result of a complex study of the Code provisions, it was established that the anti-doping system based on the principle of strict liability contains a combination of procedural and substantive legal mechanisms that lead to the public perception that the system is unfair, allowing unequal treatment of athletes and failing to respect the balance of interests. Based on the findings, the authors propose measures aimed at improving the process of adjudication of anti-doping rule violations.