I've been doing that with NBA 2K11 as well. Yes it takes up memory, buy having 2-3 saves will save you a lot of headaches if one of the files get corrupted. Player 2-3 games and then save in both File 1 and File 2. Then load File 2 for 3-4 games and do the
same thing again, but use File 1 again when loading the save.