The NBA play-in was introduced in 2021 as it was initially put in to help even things out during the covid season. After a season of it, the league liked it and decided to make it permanent. I actually think it’s good for the game and makes the playoffs more fun to watch.
NBA play-in tournament format
The No. 7 through No. 10 seeds are all in the play-in tournament to see who advances for the final two spots in their conference playoffs. The No. 7 and No. 8 seed play in a matchup which works like double elimination. The winner of the matchup advances as the No. 7 seed and will matchup as the No. 8 seed. The next matchup will be No. 9 seed vs. No. 10 seed. Whoever loses this will be out, while the winner will take on the loser of the No. 7 and No. 8 matchup. The winner of this fall matchup will be the No. 8 seed and the loser will be out.
Basically the No. 9 and No. 10 seed must win two games to advance and they must win both games they play. While the No. 7 and No. 8 seed get two chances to win one game to advance.