Another slow day in the basement?
Careful with that joke, it's an antique.
Personally I'm with seemingly just about everyone - I'd rather keep both, and it's a testament to how good they are that nobody seems to willing to part with either.
But in the likely event we don't keep both, I go with Tatum. Brown has made a huge leap this season and looks like a future All-Star, but Tatum is far ahead of where Brown was at 19. His poise, shooting stroke, and the way he makes the game look easy are just incredible for a teenager. I expect regression but right now he rates as one of the best shooters and best clutch players in the league, and his defensive instincts look great for a rookie. He's the one you've got to go with in my opinion.