This is a playstyle question. If the Celtics can keep Irving's and Luka's assist numbers down, while forcing them to take tough shots, I think we can beat them.
I'd like to see them hunt Luka early and often in these games. He's a decent weakside team defender, but he's lousy on ball. Make him work. Make him change directions. That should wear on his offensive ability late in games.
I'm really curious how the Mavs play. They got to keep Gafford and Lively near the basket on defense all last series (and against the Clippers), but the Cs should be able to force them out of the paint. If they switch everything, I think the Cs should be able to feast.