Idle curiousity: Quads Odds?

Are you more likely to hit quads with a pocket pair, or three on the board?

I know I have hit it more with pockets, but I figure that is because I am likely to be playing hands with pocket pairs, when they quad up. But if three sixes come on the board, I already folded 98% of hands that had a six in them.

Pocket pair for a vast majority of us imo. Most of the players wouldn't be limping in with low cards and going to the turn and or river with mid or even low pair. If you're looking at straight odds without player tendency I'd definitely go with pocket pairs once again.

The odds of limping in with two different cards would be probably favored if, and only if, you look at the other end of the spectrum. Say you were a drastically loose player like Gus Hansen used to be. A few players per million might be able to flip the probability and make two different cards quad a minuscule amount more of the time than pocket pairs.
Some solid numbers would be nice to back up my opinion but I'll leave that up to someone else.

I have been pondering it. I am pretty sure that if you just deal endless 10 player hands, you will get quads with 3 on the board more often than with pocket pairs. But we don't see it because so many crappy hands are not played long enough to quad up.