Right now I am working on a Black Jack game for iOS and would like to have a leader board that shows which players currently have the most "money". So if they get a high score and then lose "money" it would update their high score to match the users current amount of money, which would be less than before. Is there any way to do this with Game Center?
Things have changed since iOS7. Now you can change the "Score Submission Type" to "Most Recent Score" instead of "Best Score". This is an option in iTunes Connect when you create a new leaderboard.
Sorry to disappoint you but Game Center only writes a new score if it is higher than the previous one. You can reset the score board via iTunes Connect, but that will lose all previous users info.See the comments link
来源：https://stackoverflow.com/questions/7697478/update-a-score-already-submitted-to-game-center