None, the automated system doesn't work like that. They've updated it to now it runs through and if it detects a word or so in your gamertag that's offensive, it will be required to change. Once it's pulled up though, because people can do things with their names like "IF u * *", then whoever is monitoring at that time will have to confirm it. the people at xbox live that you call, that handles all that stuff do not have privileges to make you change your name on their own. It has to be approved either by; A: the automated system, or B: the appropriate authority. Now, not only that, but you're also risking people who've filed complaints on you. They can get suspended for abusing the complaint system.
Whoops: I didn't mean to say none, that was depending on your name. If you get about 50 complaints within a months time, they'll require you to change it. IF it's offensive.