The draft rules allowed a team to draft a player in his 5th year after high school graduation, which Bird was at that point because he went to Indiana originally but transferred his first year to Indiana State. The Celtics had the time between the end of his college season to sign him, otherwise he would go back into the draft. It was a huge risk for the Celtics, if he didn't sign they would end up with nothing for the prior year's draft pick. Bird, even though already drafted, stayed to play his senior/5th year at Indiana State and took them to the college championship and lost to Magic.
As to the show Winning Time, I finally watched and quite enjoyed it even though I hate the Lakers more than anything. I really enjoyed the Roger Murdoch/Airplane scene and Kareem telling the kid off after he asked for a picture with him. I hated all of these Laker players and Riley growing up so it’s weird to watch this without nearly as much hatred towards them as I used to have.
As to the other NBA topics in this thread, the Celtics Big 3 was nothing like the Heat. They were all actually older/very close to past their prime type players in Garnett, Pierce and Allen. The Heat put 3 of the Top 10 players in the league at the time together. I grew up a Celtics fan as my whole family is from Boston but I actually grew up in Miami so I have been a Heat fan since their first season. I actually liked Lebron when he came to the Heat (as a fan of the team would) and didn’t blame him for leaving the Cavs as they never put a good team around him. That being said, I hate Lebron for leaving Miami the way he did. His PR folks made it all about going home but the truth was he saw Wade and his injured knee and the whole team aging and realized he couldn’t win more there so he went back to the Cavs who had a budding super star in Kyrie and the #1 pick which he knew would be traded for Love. Love at the time was considered a top young PF in the league. Once Love injured his back and Kyrie was injury prone he bailed on Cleveland and went to LA to try and form another super team with Unibrow. Lebron is one of the greatest ever but the multiple moves to a better situation is not a good look to me.