The AFL’s illicit drugs policy is a farce that fails to deter players. It’s not just because of the controversial “three-strikes” rule; the sheer lack of tests also undermines the policy’s credibility.

No one seriously doubts that drug use is widespread in the AFL. John Worsfold, West Coast Eagles coach, said around 20% of his players admitted using drugs. Disgraced Carlton player Laurence Angwin claimed “five out of the nine” in the leadership group were taking drugs the night before he was sacked. Former player Dale Lewis nominated the figure of 75% of players using drugs. Hawthorn great, Dermott Brereton, famously lamented a recent Mad Monday where “there wasn’t a beer in sight”.

The AFL went to court to stop Channel 7 using a list of up to seven drug users from just one club. And then there’s Ben Cousins, who evaded testers despite his ongoing and very public “substance problem”.

How can all this gel with the official drug testing results: just nine positives in 2006, down from 19 in 2005, for 650 players?

A statistical model of football drug-testing can go some way to providing an answer. We know how many players, tests and “strikes” are allowed. We also know which drugs are popular with players. From published sources, we know how long after use various drugs stay detectable in the system. So if we assume perfectly random testing – that is, all players face an equal chance of being detected at any time – we can estimate a player’s chances of getting caught.

We can also estimate the chances of them exceeding their allowed number of strikes and being “named and shamed”. (The details of this model can be found here).

Of course, such an analysis requires us to consider a range of different footballer drug-use scenarios. Consider the most extreme case: a player using cocaine weekly over their four year career (the average footballer’s tenure). Under the AFL’s previous regime (500 tests per year), such a player could expect a 58% chance of being detected by the AFL and a mere 6% chance of ever going before the tribunal. Even under their revised 1000 test regime, this player faces only a 26% chance of being publicly sanctioned. The results for amphetamines are similar. Who’s that going to deter?

AFL CEO Andrew Demetriou cites deterrence as a key factor in the AFL’s policies. His NRL counterpart David Gallop declared “three strikes” was not enough of a deterrent when his league moved to “two strikes” this year. While Mr Demetriou likes to paint the AFL as being the toughest code on illicit drugs, this is not borne out by the model’s numbers.

Drug Use Profile Detection Sanction
Cocaine, Weekly 83% 94% 26% 77%
Ice, Fortnightly 73% 88% 15% 62%
Ecstasy, Monthly 64% 80% 9% 48%
Valium, Monthly 76% 90% 18% 66%
Cocaine, Monthly 34% 48% 1% 14%

NB: Percentages are career probabilities. AFL assumes (revised) 1000 tests per year across 650 players with “three strikes”. NRL assumes 1100 test across 450 players with “two strikes”. All assume average four year career.

To provide a credible deterrent, any drug testing regime has to offer a reasonable prospect of detection and sanction for the most egregious users. This model shows that AFL players can regularly take a range of “party drugs” with a much lower risk of career impact than NRL players.

Can anyone really argue that a 1% chance of a tribunal hearing will deter risk-seeking young footballers from taking cocaine?

If the AFL accedes to Sports Minister George Brandis’ demands and scraps the “three-strikes” policy, the AFL may be able to access some of the $21 million fund for drugs testing of professional athletes. A “two-strikes” policy and an increase in testing volumes will increase the deterrent value of the tests, plus allow earlier interventions.

The AFL executive and the players’ union are keen to deal with illicit drug use as a medical, rather than disciplinary matter. While keeping things under wraps in this way is clever in the short-term, failure to offer credible deterrence may ultimately do more harm to the sport and the players.