This Cache CT setup is very effective in matchmaking, Faceit, and ESEA. Great for beginner players and experienced alike because it is so versatile. The colored boxes are a general guideline to where the player should be. Switching up your position can be a good thing if you have played the same position a lot.
Green: The primary goal of this player is to jiggle main, and call for backup if he sees someone or needs help. When you play this position you should try to stall as much as possible when the opponents commit to the bombsite, so your teammate on highway can help you out if needed. The difference a few seconds more alive makes can win you the round.
Yellow: The purpose of this player is to support mid and A site when they need it. Early round he should be helping out mid until you have mid control. When you have mid control, you should help out where it is needed. You should always be listening for sound cues from A main, so that you can inform your teammates. When helping in mid your primary role is to jiggle garage. If you smoke garage, you can jump on top of the white box so that you can challenge boost.
Orange: The main mid player. Preferable has an AWP. If you are solo in mid you should be focused on garage and only peeking boost every couple second. When playing with a teammate highway you can take a bit more risk and hold an angle onto boost more often.
Blue: This player should float around in checkers. Playing with an AWP in this position can be very effective because it is a very hard angle to challenge. Ask for flashes from purple if needed.
Purple: The primary purpose of this player is to support the teammate playing inside checkers with utility usage in the form of popflashes and smoke grenade / molotov grenade to slow down a potential B site push.