Small and medium pairs are among the trickiest hands you'll encounter in Seven-Card Stud. Frequently you'll get into situations where it seems that a modest pair might be the best starting hand, but you don't really know. Even if that pair is ahead on third street, it's not a big favorite over much of anything. So you need to be cautious with your smaller pairs in Seven-Card Stud, both on third street and on later betting rounds.
There are a few factors you should think about before putting your money in the pot on third street with a small or medium pair. The primary consideration is the previous action. If you're sitting with a pair of 7s and there's a completion and a re-raise before the action gets to you, you shouldn't even consider playing them. You're almost certainly up against a bigger pair and there's no good reason for you to draw. Similarly, if a very tight players completes with a Queen showing while sitting to the immediate left of the bring-in, you may want to give him credit for a big pair. Get rid of your small pair and wait for a better opportunity.
You should be more willing to play a small or medium pair if there's only a completion before the action gets to you. But even then, you need to look at a few factors before deciding whether or not you should continue with your hand. First, determine if your cards are live. If you've got split 7s with a King kicker, you can muck the hand if both a 7 and King are out. You'd like every card that would improve your hand to be live.
Another factor to consider is the size of your kicker. When starting with something like a pair of 6s, you'd like your kicker to be higher than the door card of the person who completed the bet.
If you play a small or medium pair on third street and are against a single opponent, you'll usually call a bet on fourth street as well. Of course, you'd most likely want to fold if your opponent pairs his door card.
The tougher decision is likely to come on fifth street. This is where the bet sizes double. If you call on fifth, you're pretty much committing yourself to calling the rest of the way. When deciding whether or not to call on fifth street, you need to look at the cards your opponent has caught on the previous two streets. If he started with a Queen up and caught two cards that are higher than your pair - say a Jack and a 10 - you should fold to a bet. Even if your small pair is best at this point, your hand is very vulnerable; you'll win a showdown only about 50 percent of the time. And if your opponent does hold a higher pair, you're in serious trouble. But if he catches rags and your cards remain live, then you'll want to play the hand to showdown and hope your pair holds.
There's no question that small and medium pairs are among the most challenging hands in Seven-Card Stud. But if you look carefully at your situation on third street and consider the previous action, the size of your kicker and how live your cards are, you're more likely to play the hand well.
[From Full Tilt Poker]