Against good players small pocket pairs from OOP are rarely profitable.
If you are the type of player that limps in with any small pocket pair no matter what the position or opens for a raise and calls a three bet if the effective stacks are deep enough you might want to start rethinking your preflop strategy especially against good players. In my normal game, which is $5-$10, I normally open any pocket pair that I will play when I am first into the pot. But in smaller games like $5-$5 where raises get many calls and you do not have the normal stack depth to barrel people off of hands I usually limp.
I have always preached the rule of 15 times the raise size in order to profitably set mine. To put it simply this means that if someone raises to $20 you need to have at least $300 effective stacks in order to call. You do flop a set more often than this but this little equation tries to take into account the times when you flop a set and your opponent misses the flop or won’t give you action due to overcards to their pair.
But I think, especially in today’s games where even recreational players will do some light three betting, against good players it is rarely profitable to play small pocket pairs headsup as a limp call or calling a three bet from out of position. In fact I have even heard some of the best no limit players talk about three betting or folding pocket pairs out of the blinds when a tough player opens from late position. The simple fact of the matter is usually you are going to miss and unless you are prepared to make a move at the pot you will lose. A lot of the time you will be forced to fold the best hand. And when you do hit your set your opponent may be so wide that he will not pay you off or he is skilled enough to get a way from his hand.