Rules:
You can change three discrete moments / events from Celtics history per decade, starting in the 1970s. Those moments can't be game outcomes / missed shots, etc., but they can be re-doing draft picks, trades, preventing injuries (or a couple of obvious deaths, sadly), not signing certain free agents, etc. You may second guess one decision in the 2020s.
Please try to only change things that we know could have happened (i.e., no trading Dee Brown for a Cavaliers #1 that eventually became Lebron).
Go as far down the rabbit hole as you want. For instance, if we hadn't traded for Kyrie, then we could have done X, Y, Z.
Use this format:
1970s:
1.
2.
3.
1980s:
1.
2.
3.
1990s:
1.
2.
3.
2000s:
1.
2.
3.
2010s:
1.
2.
3.
2020s:
1.