I guess this has probably been done before in here, but I couldn't find anything definitive in the search.

How often are you likely to have a set over set situation on the flop? I guess there are a lot of variables, but what if we just assume that every pocket pair dealt makes it to the flop?

I really begin to question the relevance of these questions...

It all depends on the situation. How many players are in the pot, how many of them have a pocket pair, which pocket pair they hold, etc etc...

If you have 2 players with both a pocket pair... player 1 will flop a set/fullhousewithset/quads 12.1% of the time, and if this happens, player two will have a set/fullhousewithset/quads 8.55% of the time... (using StoxEV to simulate)

So if you go to the flop with 2 players holding a pocket pair, set vs set will occur around 0.121 * 0.0855 = 0.0103455. Thats a bout 1% of the time.... or 99 to 1.

If you are asking what the probability is that if you flop a set, you're up against a higher set... that's a different story. If you are on the flop with XX in you hands, and the flops comes XYZ where X is not the highest card on the board... you'd have to calculate the odds of anybody at the table and still in the hand has the hand YY or ZZ, and that depends on the situation... (players in the pot, their ranges, and so on...)...

Just use StoxEV...

Suppose there's a raise and a reraise. Are you going to stay in the pot with 33? You also need to account for that fact that people fold pocket pairs preflop. So if the odds of having set-over-set are 99-to-1 (assuming everyone plays every pocket pair), then the probability is a bit more subjective.

It could be more like higher depending on how wild a table is playing, how tight a table is playing, how smart a table is playing, etc.

With big stacks and a tight 3 better (so I get paid off when I hit a set) I might play 33, but 97% of the time I'll fold there...

I'm never worrying about that 99 to 1 odds that he could have a higher set. Most of the time, when there's a lot of action... and the board is something like AK3 when I have 33 and called a tight 3 bet preflop... I might get worried. But at 50NL or lower you can't fold those 33's ofcourse... people with AA KK do that, but also AK...

If it's set over set, I say: "nice hand", and move on...

For bad beats, I say: "nice hand".

For set over set, it's more like: "^@!*&^$@!&^%^!()@&^%$*(&!@*(#$&!@(%^@(!*&$*&!@$^( %^#*()&%*(!@#&$*(&!@%*^@!^@!*&^$@!&^%^!()@&^%$*(&! @*(#$&!@(%^@(!*&$*&!@$^(%^#*()&%*(!@#&$*(&!@%*^@!^ @!*&^$@!&^%^!()@&^%$*(&!@*(#$&!@(%^@(!*&$*&!@$^(%^ #*()&%*(!@#&$*(&!@%*^@!^@!*&^$@!&^%^!()@&^%$*(&!@* (#$&!@(%^@(!*&$*&!@$^(%^#*()&%*(!@#&$*(&!@%*^@!"

hehe me too... but I didn't feel like typing all that

With the help of Poker Tracker or Holdem Manager, try an empirical estimation. At least, you will have a "situational" number.