something that occurs me is that the server has to keep track of every point of every player to track collisions, basically a table of "playerID,x,y,timestamp",

something that occurs me is that the server has to keep track of every point of every player to track collisions, basically a table of "playerID,x,y,timestamp", so when the client gets a status update, instead of receiving the current position of other players, he would get the moves of all players since the last update, limited to the x1,y1,x2,y2 of the client's viewport. Then the client would normalize the data (over time)?