The biggest threat to the Celtics not winning the title, are Tatum and Brown. Will they both finally show up and play with a killer mentality every single night of the playoffs? Will they take every game seriously? Too often in the playoffs, they have this laissez-faire attitude that every game doesn't matter, and they'll just get the next one if they lose. They need to stop playing 6-7 game series each round, and put teams away in 4-5.
This may be on the team as a whole, but win every home playoff game. Their record at home in the playoffs the last few seasons, is simply embarrassing.