What is the value of home-court advantage in the NBA?
Preston Johnson aka (@sportscheetah) will write a number of guest posts throughout the NBA season for The Action Network. To start, he breaks down NBA home-court advantage headed into the 2017-18 season.
For the last two months, we have all been busy firing at football lines and tweaking our numbers throughout the process. In the midst of tackling both college football and the NFL, however, some of us super degens also start preparing to bet the NBA.
The Association threw us a curveball for the 2017-18 season by adjusting schedules to provide more rest throughout the season to players, which required starting the regular season significantly sooner than usual. For those who have been scrambling to dust off their hoop models or to make team power rankings — and believe me, I get it it as I set individual evaluation/contribution values for every single player in the league before I construct mine — I want to provide you with a shortcut by answering questions I get every season about valuing home-court advantage in the NBA.
Taking a look at football again for a moment, I’ve noticed that the majority of recreational bettors seemingly automatically assign three points for home-field advantage. While that is generally “good enough” for a recreational bettor to get an idea of what a spread should be in a particular matchup, it can result in making less optimal bets by affecting your perception of the edge you have in a game.
This leads me to those questions I get asked each year pertaining to NBA home-court advantage:
"What in the world do I give a team in the NBA for home-court advantage? Do I arbitrarily assign three points, like I do in football, to every home team, as a recreational bettor, or not?"
To help answer these questions, I used historical data for every single team in the NBA to derive a true advantage based on average margin of victory at home versus on the road — all-time. Unsurprisingly, certain teams have had a more significant (or less significant) home-court advantage over time than just the aforementioned generic three points.
I weighted these home-court advantage values slightly for recency. For example, the Golden State Warriors’ home-court advantage value the last five seasons is quite a bit higher than their franchise historical average. We can attribute at least some level of correlation to a team’s personnel and their margin of victory at home versus on the road, and the 2017-2018 Warriors’ roster is very comparable to what they have had the past five seasons.
Here are the home-court advantage values I will utilize to make my numbers and projections for NBA games this season: