[Precept2]

I've seen a similar hand in a live tourney at the Trop in AC that I eventually won. 12 left in tourney, so we're playing 6-handed.

Pre-flop:
UTG (which is me) has 66 and raises
SB has 22 and calls
BB has 33 and calls

Flop comes 6-3-2 Rainbow.
I bet.
SB Calls.
BB raises all-in.
I call.
SB folds & shows his trip dueces. I was pissed, because I should have taken them both out.

Anyway, here's the math:

The probability you flop a set is about .12 (which is about 7.2-to-1).

3 people flopping sets is (.12)(.12)(.12)=0.001728

You need 8 of the remaining 50 cards. Whichever one you get, you need 4 of the remaining 49 cards.

The Probability of flopping the 2-gut straight is (8/50)(4/49)=.013

The Probability of 3 people flopping sets & a 2-gut straight is (.12)(.12)(.12)(.013)=.00002351

If you didn't notice, I'm a math teacher who just happens to teach Probability & Statistics. I'm pretty sure those numbers are correct (even though they've been rounded slightly).