how exactly does the beacon score work. I know it is a number between 400 and 850 the tells creditors how high of a risk you are, but how much can you expect it to fluctuate in a year? What is the points value of say a late debt of 30 days? Or 120 days? Or a year's worth of timely payments?

There is really no specific answer to your question. There are so many things factored into FICO's algorithm.

For example, a 30 day late payment might not effect my credit as much as it would yours or someone else's. The best place to learn about this would probably be at MyFICO.com.