Odds of a 1300 player beating a 2200 player?

What are the odds?  I have a friend who is 1312 uscf and matched up against a 2230, what would the Vegas over/under be? 

I actually have seen it happen once, but only once before, where a 1368 beat a 2209: http://www.uschess.org/msa/XtblMain.php?201503286992.1-14105448

Theoretical Probability of Winning Based on ELO Ratings

Your rating: 1300 Opponent's rating: 2200

Probability of winning: 0.00559196730883478

== about 17.9k to 1

search for "chess rating difference probability".

How would a 1300 even be paired to a 2200 is the real question

I've seen an 800 rated player beat a 2000 rated player.

He actually beat two of them

Then he got caught cheating.

"2) In practice, huge underdogs (like this) preform better than the rating math predicts. In the past, various changes have been suggested to improve this."

Interesting! I guess it makes sense.

It happens often in small swiss tournaments (10-20 entrants).  I'll be playing above my rating, win 2 or 3 games, and in the fourth round, the 2200 and I are paired.

I remember early in my chess playing career of being accused of being a sandbagger because I placed high in a tournment by beating a 1900 player, an expert, and taking a draw with another expert. My rating at the time was around 1300. I noticed also later in my USCF 'career' , I mistakenly played in a g/30 tourney where I lost several games mostly due to time trouble. I didn't realize at the time that g/30 games counted toward my regular rating (unlike g/5 or g/15). I dropped from a 1710 rating to in the high 1500s. Strangely enough, I later noticed on my USCF label (I am a life time member) that my rating dropped further to something like 1465 (rating adjustment?) even though I have not played an USCF rated game in over 20 years.

After a long time not playing chess regularly (I did play a few times on Yahoo games, but there tend to be a lot of fast matches only there) I found  chess.com about a year ago or so and I have just increased my rating to 2026 and my rating on another site is higher, though on that site the rating formula is different, so I think it's about the same (I certainly play at the same level on both sites). I have started to study some openings more and improved my tactics to a degree. I also have reviewed endgames I am familiar with and looked at various ideas.

Here is a recent win against a grandmaster played at 5 days/move.

1.e4e5

2.Nf3d6

what is going to happen. Usually they tromp all over the competition, but sometimes they get ambushed by something new.

(sorry, don't know why, my comment got cut toward the end).