Here we go again.
ABC News reported that Ricky Williams, former NFL star, proclaimed himself as holding "the world record for most times drug tested". (link) He said he was tested 500 times.
During this 11-year career, Williams failed the test four times. So there is one thing we know - the drug testing regime is not much of a deterrent.
Since the athlete knows when he is juicing or not, he is privy to an estimate of the false negative / false positive rates of the testing regime. If someone keeps rolling the die, he or she probably knows the tests are not that effective. In my book, I showed using some simple math that almost all juicers would pass these tests.
The number 500 itself is useless. It's all about the protocols. Is the testing really random? When are athletes informed about the test? How is the sample collected? (For example, his wife disclosed that the tester left the sample standing for 45 minutes to "go get stickers" to identify the source of the sample. Sure.) What checks are in place to prevent tricks like using other people's urine, diluting, etc.? Are there off-season testing?
It doesn't matter how many times he is tested. What we should care about are the protocols used in these tests.