8 (9 if you add a year and count 1974).
I got this here: https://www.nba.com/news/all-time-nba-finals-game-7s
Another context note I didn't look into just yet would be which teams did win on the road, or how dominant a home team was compared to the road opponent.
But 2 times out of 8, context...
I found out we weren't going to be allowed to see UNI play Missouri in the NCAAs way back when, so I went home for lunch and stayed there to watch it.
Once I left, the teacher got a TV for the room to watch the game, but it was still better at home.
It took forever to get back to it, but I finally did push through those first 2 episodes of Andor. Like the whole world says, it really ramps up in episode 3 and never lets up from there.
1 season down. 1 more to go.