On Sunday afternoon, the basketball world’s two Los Angeles squads face off at Staples Center, their shared home. Though the rivalry has historically been dominated by the Lakers, this year’s matchup features two star-studded squads at the top of the Western Conference. With the Lakers and Clippers 1 and 2 in the Western Conference standings, the thought of an exciting Western Conference Finals between the two rivals, with LeBron James going toe-to-toe with Kawhi Leonard, is a real possibility this season.
What makes a potential playoff matchup all the more intriguing is the added drama of knowing that every game would be played in the same building! That got me thinking about home court advantage in such a series. Would the home team in an individual game of a Lakers vs. Clippers series not have the full home court advantage that we would expect from a typical matchup? Or might we see the Lakers, the traditionally more popular team, maintain their home court advantage while the Clippers suffer the effects of a swarm of purple and gold fans invading their “home” games.
While I admit that playoff home court advantage may be different from what happened in previous regular seasons, I decided to examine the data from the 2006-2007 regular season to the 2018-2019 regular season (excluding the lock-out shortened 2011-2012 season). This gives us a sample of 48 total games played between the Lakers and the Clippers, 24 home games for each squad.
Next, to get a baseline of how strong home court advantage typically is in an NBA game, I went back to a simple model of a regular season game that I have used before. This model takes three variables and uses them to predict the final score of a game:
- Which team is at home.
- The difference in point differential between the home team and the road team.
- Whether or not either team is on a back-to-back.
What I did next was use this model to compute the “expected” score of each Lakers vs. Clippers game in my sample. So each game got a predicted score differential based on how well the two teams played that year, who was at home, and whether either LA team was playing on a back-to-back.
With these expected point differentials in hand, we can compare the Clippers average home margin of victory in those LA vs. LA games with the expected average from the model. Then we can do the same thing for the games when the Lakers were home. The results are in the chart below.
How should we interpret these results? Well, the Clippers and Lakers have each exceeded expectations (based on the strengths of the two teams) when playing at home against the other. So from this data it appears that home court advantage has not been any weaker for the two LA teams when they play one another. The Lakers have played especially well as the home team against the Clippers, winning these games by an average of 1.3 points more than expected. But the Clippers have also held serve when they are the home team; they have exceeded expectations by 0.1 points per game when hosting the Lakers.
At least if past regular seasons are a guide, we might expect home court advantage to still matter in a Lakers vs. Clippers playoff series. But, with the two Los Angeles basketball squads having never faced each other before in the playoffs, the playoff atmosphere may cause the effect of home court advantage to change. Regardless, the basketball world would be treated to quite a spectacle if the Lakers and Clippers met in the playoffs this season!