In the NBA playoff system, the Eastern Division champion plays the Western Division champion in a seven-game series. The first two games of the series are scheduled at the home stadium of the team with the most wins during the season. Let’s call them Team A. The next three games are scheduled in Team B’s arena, and the final two games are scheduled in Team A’s arena. This can be described as a 2-3-2 schedule. [Prior to 1985, a 2-2-1-1-1 schedule was used.] The first team to achieve four victories is the NBA champion. Thus, the series can last 4, 5, 6 or 7 games.

Team A, if the series lasts all seven games, will play four games at their home stadium, while Team B will only have three games at home. Since basketball teams tend to win more often at home than away, the A-Team is said to have “home field advantage” for the series. [Note that if the series lasts 4 games or 6 games, each team plays the same number of home and away games. If it lasts 5 games, Team B has three home games while Team A has two. This is easier to visualize if we denote the 2-3-2 schedule as AA-BBB-AA, where A and B represent at which team’s home arena the game is scheduled.]

The A team certainly seems to have been favored by the schedule. Not only do they play more home games than Team B in a 7-game series, but since the first game is played at their home stadium, they have a better chance of taking a 1-0 series lead. However, sometimes Team B wins the first game. When this happens, it is often said that Team B “stole home court advantage” from Team A. Sure, “stealing home court advantage” is a catchy phrase, but is there any basis for this claim, either in logic or in reality? results?

First, let’s look at the logic associated with Team B winning the first game. In a 4-game series, Team B now has two of three games remaining at home (A-BB); if the series lasts 5 games, three of the remaining four games at home (A-BBB); and if the series lasts 6 games, three of the remaining five games at home (A-BBB-A). In a 7-game series, they now have three home and three road games, the same as Team A (A-BBB-AA). So, from a logical standpoint, Team B has gone from having home-field advantage only in a 5-game series to having home-field advantage if the series goes 4 games, 5 games, and 6 games. They also went from an “away disadvantage” in a 7-game series to an equal number of home and road games. Understandably, they certainly seem to have improved their lot.

But does the actual performance data support the logic? In the fifty NBA playoffs from 1960 to 2009, the A-Team won the series 34 times, with a 68 percent winning advantage. Team B, naturally, won 16 series with a winning percentage of 32. Indeed, home field advantage seems to have served Team A well. However, in those fifty series, Team B won the first game of the season. series 13 times. Did they steal home-field advantage by winning the first game? Well, they won seven of those thirteen series, with a 54 percent winning record. Remember, Team B only won 32 percent of the series overall. This is a great improvement!

So, can an NBA team steal home court advantage? Both logic and historical data seem to indicate that they can, or at least erase the handicap they had at the start of the series.