I consider medium pairs as 44 through 88. Higher pairs should be played stronger and lower pairs even more cautiously than these recommendations. With medium pairs your overriding concern is to get in to see a cheap flop, because if the cost or position is not relatively predefined, you will consistently be playing these hands into a negative expected value. (-EV). There is simply no reason for that to be. In the best case scenario you are looking to flop a set