The 40-20 Rule

What does an NBA theory have to do with the AFL?

Phil Jackson is undoubtedly one of, if not the, greatest NBA coaches of all time.

After playing professionally for 12 seasons and winning two championships as a player he moved into coaching, where he won six championships with the Chicago Bulls and another five with the Los Angeles Lakers.

So he clearly knows a thing or two about winning.

In 2008 Jackson presented a theory on how potential championship teams could be identified during the regular season:

“You must win 40 games before you lose 20 to be seen as an elite team.”

This theory has gone on to be known as the 40-20 rule, with many fans and reporters keeping tabs on how teams are progressing throughout the season. It has (unsurprisingly) been the topic of many articles and social media posts since its inception.

In March this year ESPN reported that 27 of the last 30 NBA champions met Jackson’s criteria, with the 2004 Detroit Pistons, the 2006 Miami Heat, and the 2021 Milwaukee Bucks being the three exceptions.

This figure can be updated to 28 out of 31 after the Boston Celtics won their record 18th championship earlier this month. Three other teams fit the 40-20 rule this season – the Denver Nuggets (eliminated in the conference semi-finals), the Minnesota Timberwolves (eliminated in the conference finals), the Oklahoma City Thunder (eliminated in the conference semi-finals).

Can we apply the 40-20 rule to the AFL?

While the 40-20 rule doesn’t exactly translate to the AFL (which has a much shorter season than the NBA), we can still see how the theory stacks up in our game as the key belief remains the same: good teams win accrue wins faster than losses.

But like any rule, there are exceptions, such as a middle of the ladder teams getting on a winning streak towards the end of the season.

For the purposes of this post, I’m looking at the 18-team AFL era (2012 onwards). During this time teams have played between 17 and 23 games in the regular (home and away) season. As this is roughly a quarter of the length of the NBA season (82 games), I’ve adjusted the ratio to 10-5 in seasons with 22 or more games, and 8-4 in the 2020 covid-shortened season.

Between 2012 and 2023 54 teams met the adjusted 40-20 rule. Nine of these 54 won the flag, a further nine made the Grand Final, and four missed finals.

jackson-graph

During this 12-year period an average of 4.5 teams meet the adjusted 40-20 rule per year, which may explain why there are so many more teams that have lost in a preliminary final.

And the four teams to miss the finals after meeting the rule? Essendon in 2012 and 2013 (the latter due to the supplements scandal), Port Adelaide in 2018, and Carlton in 2022.

The premier in nine of the last 12 years has met the 40-20 criteria.

Richmond’s three premierships in have been the only exceptions to the rule, although the Tigers were 9-5 after Round 15 in 2017, 7-5 after Round 12, and 6-4 after Round 11 in 2020.

What does it mean for the 2024 AFL season?

After 16 rounds (and 15 games) in 2024, the only teams to meet Jackson’s rule are Sydney (13-2) and Carlton (11-4), sitting in the top two ladder positions.

Essendon missed their chance to join the Swans and the Blues after losing to Geelong on Saturday night, as did Collingwood with their loss to the Suns (although one could argue the Magpies could be judged slightly differently as a result of their two draws to this point of the season).

All other teams had lost at least five matches before winning 10.

It will be interesting to see how Sydney and Carlton perform come September.


The timeframe of this stat is limited based on what data are freely/easily available and/or accessible. Please don’t hesitate to contact me if you spot any errors in what I have presented.