This will depend on match-ups sometimes but in general, who do you want closing games for the Celtics right now and heading into the playoffs? Vote for you 5,
The way I see it, Kyrie and Al need to be on the floor. That leaves 3 spots for Smart, Tatum, Brown, Morris, and Hayward (Rozier and Baynes might get in on specific match-ups but aren't as good as the other 5).
I want Smart on the floor when it matters. Hayward is too up and down, I don't trust him. Morris has been terrific this season and has had some clutch moments for the Celtics last season and this season but both JB and JT are more talented and I think they've proven they can be trusted.
Kyrie, Smart, Brown, Tatum, Al. It's a small lineup, but those are the guys I want out there with the game on the line.