When there are around 60 players left the Mid-Game begins. Anyone who has managed to survive up until this point will almost certainly have good weapons and gear so you need to proceed with caution. The best strategy now is to use a sniper rifle and look to take out enemies from a distance, if didn't find a sniper rifle you have the alternate option of placing 4x and 8x scopes on a rifle and setting it to single shot.
The End-Game which is the final stage takes place at the center of the map so you need to make your way there collecting as much good gear as you can in the process. As you travel across the map try to avoid open spaces and always be near something which can provide cover if you encounter an enemy shooter. Keep an eye out for an automobile such as a Jeep which you can use to reach your destination faster and make it more difficult for other players to pick you off with their sniper rifles.