Did lottery reform actually curb tanking?, Reports


The NBA draft lottery goes to be a bit totally different this 12 months. Not like basement dwellers from years previous, the New York Knicks will NOT be swimming in ping-pong balls on Tuesday night time. The truth is, the Knicks can have 110 fewer successful combos than the Phoenix Suns did final 12 months — leaving them solely about half as many possibilities to land the highest choose.

Previous to the 2017-18 season, the Board of Governors voted to flatten the 2019 lottery odds, giving the group with the league’s worst document rather less assist than earlier than. The change was deemed “vital to enhance the aggressive incentives” for the groups; that’s, the reform was meant to discourage tanking. However did it work? Had been the brand new draft lottery odds really profitable in discouraging the observe of tanking?

To quantify whether or not this season’s groups tanked any lower than final season’s, I’m going to borrow an method from my fellow Nylon Calculus contributor, Michael Chang. His concept was to chart modifications in group ages over the course of the season and to take any indicators of end-of-season decreases in age as proof of tanking.

I began with the age of every participant on the primary sport of the 2017-18 and 2018-19 seasons. For every particular person sport, I calculated every group’s common age weighted by minutes performed. Then, for every group, I discovered the distinction between the typical age in every sport and the typical age for the entire season and charted these variations. Simply to clean the strains out a bit, I plotted 10-game rolling averages.

Amongst these destined for the lottery, there have been extra groups in 2018-19 who stayed the identical age or bought older on the finish of the 12 months (N=6) than there had been in 2017-18 (N=3). Correspondingly, extra lottery groups bought youthful on the finish of the season in 2017-18 (N=11) than did this 12 months (N=8).

The variety of strains present in every panel tells us a part of the story, however the colours of the strains are necessary right here, too. The colour scheme is tied to a group’s win-loss document (i.e. the variety of video games above 0.500) with darker blue strains indicating extra dire conditions. Final 12 months, the sample was predictable — groups with mediocre win-loss information (grey or mild blue strains) maintained a constant cohort of gamers (a flat line) for a lot of the 12 months and diminished the typical age (a declining line) on the very finish, solely after it grew to become clear that the playoffs have been out of attain. Groups with worse information (darker blue strains) turned to youthful gamers earlier within the 12 months, quickly after the All-Star Break. In distinction, this 12 months, a few of the darkest blue strains stayed comparatively flat all season lengthy.

Utilizing these charts we are able to additionally assign a easy tank score to each of the 2 most up-to-date seasons. For every group, we are able to rely up the consecutive variety of video games throughout which the gamers have been youthful than the group’s common age to shut out the season. Then, sum up the entire below-average age, end-of-season streaks throughout all of the lottery groups to seek out the tank score. In 2017-18, the lottery groups completed up with 148 younger-than-usual video games. In 2018-19 that sum was diminished to 107, suggesting that there have been maybe 41 fewer tanking-influenced video games this 12 months — or about Three much less per lottery group.

If you’re keen on discovering the age developments for a selected group you’ll find the annotated and interactive chart beneath. Filter by group, season, rank, or document:


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