How can I evenly assign players on a team?

I have a round based team game. I want the teams to be randomly assigned when the round starts. I know that teams have an auto assign feature, but I don't want players to be auto assigned when they join, but rather when the round starts. How would I do this? Here is a script I used:

for _, v in pairs(game.Players:GetChildren()) do
        Player = Instance.new("StringValue", workspace.Players)
        Player.Name = v.Name
        local f = math.random(1,2)
        if f == 1 then
        v.Team.BrickColor = BrickColor.new("Red")
        else 
        v.Team.BrickColor = BrickColor.new("Blue")
end
end

This script just randomly assigns players.