Croatia has been both good and bad this tournament. They are 3-2, with a bad loss to Nigeria and impressive wins over Lithuania and Spain. They have the high scorer of the tournament in Bojan Bogdanovic, who is averaging 25 a game. Big man Dario Saric is also playing well, averaging 13 points and 7 boards.
Serbia has gone 2-3, their lone wins coming against Group A doormats China and Venezuela. Serbia has had some hard fought losses though, including a 75-76 loss to France and a 91-94 loss to the US in which they missed an open three at the buzzer that would have tied it. Bogdan Bogdanovic (who has a ridiculously similar name to Bojan, but no relation) is Serbia's leading scorer averaging 13. They are led inside by Dario Saric, a center with the Denver Nuggets, who is averaging 9 points and 6 boards.
I give Croatia the edge here. They have too many players who can shoot, and I expect Bogdanovic and Mario Hezonja to have big games from three. They seem to have proven more than Serbia this Olympics and I'm not sure why they aren't the favorite. I'll gladly take them at +170.
Look for the Croatians to advance tonight in Rio.