The way I would do it: Get a board with a grid of 5x5 insets (like a Big Boggle board), a screen to hide it, 25 colored marbles (9 blue, 8 red, 1 black, 7 white), and a bag. Shake the marbles in the bag and empty it onto the board, shuffling it around until each marble is in a hole.

(Add another red marble if you want to alternate the starting team without switching their color and remove a red or blue marble each time.)