Statistical data from the Independent Commission and the World Anti-Doping Agency (WADA) indicate that Russia is the worst violator of anti-doping rules. Multivariate statistical models find evidence that Russia performed unexpectedly well at the London Games, that the cross-country pattern of outperformance correlates with the number of abnormal athlete biological passports and anti–doping rule violations, and that Russian outperformance was not limited to track and fi eld but extended to sports such as wrestling, where WADA has documented a pattern of signifi cant violations.