When my colleague Matt Moore highlighted which current 2019-20 NBA win totals to bet and which to stay away from, he mentioned a potential "NBA championship hangover effect" for the Toronto Raptors next year.
That got me thinking whether that's been a quantifiable thing for championship teams the next season. Or perhaps the public overrates such teams. Either way, it's an interesting question: Do title teams usually go under their win total the following year?
Do NBA Title Teams Have a "Championship Hangover"?
Sportsoddshistory.com has win total data going back to the 2002 season, so we have roughly 17 years of data with which to look at this question. Below is a table of each title team's wins and win total for that championship year, as well as its next-season win total and whether it hit it.
The popular example of a team excelling after winning a title is the 2016 Golden State Warriors, who set an NBA record with 73 wins the year after winning. They lost the championship that year to LeBron James, Kyrie Irving and the Cavs, but they flew past their season win total of 59.5.
That said, the 2016 Warriors seem to be in the minority over the past two decades. We don't have data on the 2005 Detroit Pistons, but of the other 16 title teams since 2002, 10 of them (62.5%) went under their next-season win total, which was an average of 57.6 wins.
The last three NBA champions have gone under their next-season win total, as have five of the last six. The last two "over" teams were the 2016 Warriors and the 2013 Heat, who were dynasty-like teams either beginning or in the midst of their multi-year runs.
It's unclear whether the Raptors are a one-year wonder, but the last such team — the 2011 Mavericks — had a low win total of 44.5 the year after their title and went way under with just 36 wins, easily the worst follow-up season to a title over the last 20-ish years.
That 2012 version lost several key contributors, including Tyson Chandler and J.J. Barea, and it's possible the Raptors could as well, with Kawhi Leonard, Danny Green and Marc Gasol all potential free agents.
If we remove from the sample the 2012 Heat, who played in a lockout-shortened season, only three of the 16 teams had a next-season win total higher than their actual win total in the championship year:
- 2018 Warriors: Won 58 games, win total of 62.5 in 2019
- 2017 Warriors: Won 67 games, win total of 67.5 in 2018
- 2002 Lakers: Won 58 games, win total of 58.5 in 2003
Of note, all three of those teams went under those higher numbers. But the remaining teams all saw their next-season win total decrease at sportsbooks, including this year's Raptors team, which won 58 games en route to its title but has a win total set at 52.5 for next year.
Likely incorporated into that number, however, is the potential departures of Kawhi, Green and Gasol. Especially if Kawhi leaves, the number will likely fall into the 40s, and they'll look even more similar to that '11 Mavs squad.
All in all, there does seem to be value on betting the unders on title teams' next-season win totals, even if it's much lower than their title-season number.
