how high is the pot and which overcards hit? How many people are in the pot? How many people called after you and before the button? Were the blinds getting good pot odds
if they were in the hand? If you had something like 66 and the flop was 789-r, Then betting might not be a bad idea if there are only 3 to the flop, if there are 2 to the flop you may be able to bet 1/3 or 2/5pot size bet and get them off the hand. If you have something like 99 and the flop is 10JQ-r, I wouldnt' bet if there were 3 people in the hand, and the only way I would feel safe betting in isolation would be if the SB or BB were in the hand. How many people to the flop is going to be your biggest variable when answering this question, and honestly you haven't invested much, so you don't have much to lose and when there are 3 to the straight on the board it is so easy to overplay and overvalue your hand when you have the low end. The only time you want to make a semi-bluff w this hand is suggested above. You really shouldn't invest much more into this pot unless you are late in a tournament and the pot odds
are great. I would definitely stay away from the hand if there are more than 4 people in the hand, I may only check call if i do hit my straight but more than likely im not investing anymore at this point. When is it in the tournament? or is this cash game? Either way the conclusion is clear there is no value to bet this flop when the hand is limped preflop. There is definitely no value in a cash game so you better know your opponents if you think of playing this hand at all in a cash game! The point here is value and once you limp in mid position w a hand like this and the flop is as described you shouldn't invest much more in the hand. Definitely not in a cash game! And just about the same in a tournament, unless its a really deep level. Then you should consider a small bet to see where you are and maybe be able to take/hit the hand on the turn/river. Good luck in future plays and remember value and the people you are playing against!