I've been doing a couple of under 4 yellows and been really successful with them. I noticed that only 1 game out of all played has gone over 4 yellow cards. The rest usually cruise at 2 or 3.
Tomorrows game with Argentina is tricky, and i would recommend to stay away from it. A South Korea player said that they will be fouling Messi to stop him, so i wouldn't be surprised to see a couple of yellows just from South Korea.
Better be safe than sorry and stay away