Like almost every other testing program, baseball's program uses a testosterone to epitestosterone (T/E) ratio of 4:1 as a screening device. Unlike most other programs, however, the fact that a sample has a T/E ratio below 4:1 does not mean that sample is free from further analysis.
The characteristics of every sample, including the T/E ratio, are analyzed at the WADA-certified laboratory in Montreal and the laboratory determines which samples are subjected to Carbon Isotope Ratio (CIR) testing.
All samples with a T/E ratio above 4:1 are subjected to CIR but so are many samples with a T/E ratio less than 4:1.
Christiane Ayotte, the director of the WADA-certified laboratory in Montreal, stated: "The procedures used in the Montreal Laboratory make more extensive use of CIR than those used in other labs, and there is no doubt that baseball's program detects testosterone positives that other programs would fail to detect."