Hi, I’ve been watching a lot of hand history reviews lately and one thing I noticed is that very often I see people 3-betting hands like 88 or 99 when still being kind of deep stacked (50-75bb). I’ve mostly just been copying it but without understanding why this is profitable

I can see why someone would 3-bet with suited connectors like 67s or smaller pocket pairs like 55, since it will miss most of the time you can still represent something big after 3-betting, but if you do the same with 99 aren’t you wasting a lot of value by making hands that you would be ahead of fold, while only being able to get called by hands you would basically be flipping with like AJ/AQ/AK?

If they will mostly only be holding AJ+ on the flop if they flat your 3-bet, won’t they just always be folding on flops that are good for you and calling you down on flops that you would prefer to make them fold? For example, the flop is 368 and you’re holding 99, if you 3-bet preflop wouldn’t you have folded out any hand your opponent could be holding that you could get value from on that flop? And hardly ever someone would be floating with overcards on that flop after you 3-bet..

And if the flop comes QJ7 and you’re holding the same hand, again after 3-betting preflop, where you could usually c-bet with 99 if you wouldn’t have 3-bet I now feel like I have to just check-fold because it hits their 3-bet flatting range much harder..

I know I’m missing something since all of the players that play it like this are way better than me, but right now to me it looks like you’re setting yourself just up to making no profit postflop everytime you get flatted after 3-betting middle pocket pairs.. and if you just 3-bet, knowing that you will make no profit postflop while just trying to make your opponent fold preflop, why would you waste a hand like 99 instead of doing it with something weaker? 

Really hope someone can explain!