In the playoffs, where you might presume that battles between the very best teams would yield more upsets, the opposite has been true. Teams who earned home-court advantage have won 80.9% of all playoff series since 2005. That figure was 87.5% in best-of-three series (14-2) between 2005 and 2008, but has only dropped to 78.8% in best-of-five series (41-11) since 2009.
As the beginnings and ends of playoff series, home dominance weighs even more. Host teams have won 85.3% of Game 1s since 2005 and have gone on to become Final Four qualifiers in 89.7% of those series. But even more than winning Game 1, hosting the final game of any series has been the best guarantee of success.
Nine do-or-die Game 3s between 2005 and 2008 produced a lone rode winner, Baskonia over Panathinaikos in 2006, giving home teams a win rate of 88.9%. In the best-of-five era since then, home teams in Game 5s are unbeaten at 15-0! That's a combined 95.8% success rate for home teams in do-or-die playoff finales. Only starting a best-of-five series 2-0, which has resulted in Final Four qualifications in 25 out of 25 instances, has been proven to be as much of a guarantee as hosting the final game.
Could this season be different? There are reasons to consider that possibility.
One, Zeljko Obradovic is coaching sixth-seeded Partizan Mozzart Bet Belgrade without home-court advantage against third-seeded Real Madrid. Obradovic has won 10 of 11 playoff series since 2005, all except the aforementioned loss by Panathinaikos to Baskonia in 2006. He also owns the only 0-3 sweep in playoffs history by a team that started its series on the road, his 2017-18 Fenerbahce Istanbul team that proceeded to lift the trophy at the Final Four.
The other, broader reason to believe this season could be different is the closeness of the regular season. Since all teams began playing all others in the 2016-17 season, there has never been so little daylight between the playoff teams in terms of victories.
