Activision/Infinity Ward: Please introduce an Official MatchMaking Ladder system for Call Of Duty 4 Remastered. Players would be given ranks according to the number of ELO  points they receive from winning matches against other players in a 5-versus-5, for each win you receive ELO points and the opposite when you lose a match you get deduced a certain amount of ELO points, which means players would either advance to a higher rank or unrank to a lower one according to their Win/Losses.

Games such as League Of Legends, DOTA2, Counter-Strike:Global Offensive, each have their own competitive scene and matchmaking system which gives the player the freedom to choose between playing for fun on dedicated servers and unranked games or playing competitively against other players in a MatchMaking ranked game. 

Call of Duty 4 Remastered has the simplicity to make the game very competitive, and self manage itself with MatchMaking system which is already proven to be a great motivator factor for a large playerbase to keep playing an e-sport game.