Who Should Start At Shooting Guard?

The Boston Celtics pretty much have they're lineup set, the only question left is who should start at SG? It comes down to Marcus Smart or Jaylen Brown. And it's a tough one. With the departure of Avery Brady and Jae Crowder, Coach Brad Stevens may want to add a bit of defense into the starting lineup, if so, adding Smart would be the most logical move. Smart doesn't provide too much on offense, but he is a good defender that makes scrappy plays everywhere on the court. On the other hand Jaylen Brown is a player that can also play good defense, but more importantly has a offensive game with a respectable three point shoot, unlike Smart. Who do you want to start at shooting gaurd?