Narrowing down the list

I should be recieving the Save the Date magnets sometime today and now it's really getting real! This is the part that I hear is the hardest, narrowing down who can come vs. who can't. I think I've got the list in relatively good shape though.

**NERD ALERT: I'm using a spreadsheet in Excel to say the name of the person, if they can bring a guest, and the percentage chance I think they can come. For instance, my mom is 100% yes, whereas my cousin who lives in Japan is a 0% yes. This is helping me calculate a number of those that actually may attend vs. the number of people receiving an invitation.

So basically when I got engaged I loosely said out loud to my coworkers that "you're all invited" and dammit if I'm not eating those words right now... I've looked closely at the list and if I invited all of my co-workers and 100% of them came, that would be 20% of my guest list... Granted I work for a small company and I also took into account that at least 1/2 of them wouldn't attend but I didn't want to gamble and take any risks. I cut the list down, way down. I'm sorry to those I'm not inviting but if they've ever planned a wedding/will plan a wedding they'll understand.

Then there is the case of those that are friends of friends that I'm not very close with that actually ASK me to come to the wedding. Well SPIT! If I invite you then where does the line stop?

So recently I sent out a facebook blast to a few too many people asking them their addresses. Hindsight is telling me that many of those people are actually on the B-list and now I'm just trying to figure out how I'm supposed to skirt the fact that many of them may not be on the A-list. YEESH!

Let me know your experience in cutting down a list and how you made your tough decisions!