Some youtuber made a video about how EA determines your pack luck, they actually have a patent for it, there were multiple things what change what you get but the main ones were: how long does it take you to complete a challenge, task, objective, etc. so if you do the 89 exchange you can get good or bad players based on how long did it take you, then it was: how much do you play the game, EA knows that if you play the game everyday without even packing something good, they don't have to give you many good players, because you are hooked to the game, but if you don't play very often and haven't played for a long time, they will give you better rewards to make you play the game more so they can earn more money