The NBA and ABA merged in 1976 after years of negotiating the terms and conditions on the rules and how the new league will be structured. The leagues themselves were much different in many different ways, and the merger of the two meant a new age when it comes to basketball and how it's played. It also meant more teams would participate, and the pool of talent increased quite a bit. The NBA was filled with more talent; however, it missed that streetball and fun element to the game, which it hoped to achieve by adopting some things that the ABA already had in place.
Hubbie Brown, who is a retired basketball coach who is still working as an NBA analyst, said in a book about ABA all the things that made that league more attractive for the fans in comparison to the NBA. The ABA, for example, adopted the 3 point line before the NBA did, and as a part of their All-Star weekend, they had the dunk contest, which wasn't appealing to the NBA at that time.
"We're ahead of the NBA in so many different ways. We have the 3 point play. The NBA is saying it's a gimmick, but it's one of the most exciting parts of our game. We use pressing and trapping defense, something you don't see in the NBA. We have an All-Star weekend with what we call a Dunk Contest where we have officials judging dunks performed by our best dunkers."
After the merger, Brown said he is proud that the NBA adopted so many things from the NBA except the famous red, white, and blue ball, which was a trademark for the ABA. He also gave an interesting comparison between the leagues saying the NBA is was structured in a way that it seemed it was scripted a lot of times. ABA, on the other hand, was in his mind like jazz, which means there was a lot of improvisation. The ABA also brought that element of excitement to the NBA because players were playing above the rim, and you could see more flashy moves than you could in the NBA at that time.
"About everything we did back then, the NBA adopted... Except for the red, white, and blue ball. The difference between the NBA and ABA is that the standard of excellence for the NBA is the Boston Celtics, who mastered fundamental basketball. These guys would pick n roll you to death. The ABA was Julius Erving. It was glitzy, run up and down the court... play above the rim, and we'll make things up as we go along. The NBA was scripted. It was a symphony. The ABA was Jazz. People were not sure what they did even after they did it. The players, their fashions, and lifestyles were a reflection of the times... from the huge afros and beard to bell-bottom pants and platform shoes."