The key thing to note here is, that CO has a very small gap between VPIP and PFR, which means, he is doing very little cold calling. That means, that when he does occationally cold call, its is typically going to be very weighted towards setmines. This is essentially, what these tight regulars do. They sit all day and wait for AA, KK or a set, so they can stack someone, who cant fold top pair or an overpair.
Against this kind of player I am not paying two bets with QQ on this board. But if I got to the river and hit gin, I would be tempted to raise and hope, he has that worse set. I would probably end up just calling for two reasons though. First information is never perpect, so maybe he did in fact get frisky with a suited connector type hand, and now he has a straight or flush. And second a nitty player might actually get away from a small set, because he think, you have a straight or flush, when you check-jam the river.
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