This is a guest post by Nathan Paxton.
- Prior: LA did not use performance enhancers because the tests show super-low probability.
- Data: All significant competitors used performance enhancers and tested negative, until they were caught (sometimes via a test, sometimes via old-fashioned police work).
- Posterior: Perhaps the tests’ probability of sussing out those who use performance enhancers are wrong. Revise those probabilities, in light of what we now know, make them the new “priors”, run the tests on the data, and assess how probable it is that Armstrong used those substances.