In November 2009 WADA has published the Athlete Biological Passport Operating Guidelines. 

The document specifies that the athlete's biologic passport will NOT be utilized as means to "no-start" or "health safety" precautionary sanctions, rather in the terms of a DOPING violation, incurring a 2-year stop. 

Hb e OFF-score values will be the evaluating parameters and the protocol considers the sanctionable result with a 99.9% probability of being "abnormal". 

For instance, an athlete with the following 8 Hemoglobin values collected over time: 

14.5 - 14.7 - 14.4 - 14.1 - 14.3 - 14.5 -14.9 - 14.6 (average of 14.5), will be sanctionable for Hb values above 15.2. 

If he shows a 9th value of Hb=15.3, then his case will be submitted to the attention of three Experts, who will audition him and evaluate whether to sanction him or not... 

Now, let's suppose the athlete shows a subsequent 10th value with Hb equal to 15.1: even excluding the 9th Hb value from the calculation, the sanctionable limit would jump to 15.5, allowing the 15.3 measured in the 9th sample to get back to norm... 

Such "re-entries" are always possible, monitoring the athlete over time, while a sanction is definitive and it is very difficult to rectify... 

A sanctioning standard based on statistic probability could result very unreliable and rather weak in legal arguments. 

The biologic passport turned out to be an excellent weapon to suggest and guide well-aimed and efficient surprise anti-doping controls: in my opinion it should remain and limit its function as such.