I am a young cycling fan and have not had much exposure to the race pre lance but I am really into it this year.

Its seems that the last stage is usually just a victory dance and not much happens that day.So, lets just say that after the ITT on saturday, there are a few guys within 30 seconds of each other. Will they (GC's) actually race the last stage or is that considered bad form?

IE: Is the TDF actually only 19 stages?