I think that chess is a “performing art”. Karpov called it a sport, but exactly so because he didn’t see it wise to entertain possibly speculative variations, variations which probably didn’t seem justified to do for someone seeking a sporting result.
In the game, Larsen avoids these and quickly gives the piece back to keep a clean-looking board with seemingly equal chances. The real game didn’t take me long to analyze, Tal played it brilliantly and I don’t think Larsen had any way out. But the Nb6 variation that Larsen never played took me a couple of hours to analyze! Perhaps Tal had already spent a long time over the board on those variations and Larsen saw to shift the focus.
Game 1 seemed like the best practical chance, if not ugly. There may have been a way out in there for Black in that variation. Black was up a pawn for ten’s of moves, but Crafty kept giving the nod to White the whole way. But oh yeah, Tal was looking 30 moves ahead! Probably not. I’m thinking it was his artistic instincts that told him he had the nod.
I still haven’t analyzed the part of the game leading up to the sacrifice, but suffice it to say that Tal’s style of opening treatment foreshadows the result.
Black could have played 0-0 instead of taking the knight, where 17.Nd6 BxN 18.exB gives White what seems to me to be a dangerous passed pawn, with c2-c4-c5 to follow, but White also could have played 17. Nd4, I guess, kicking Black’s queen.