I just don't believe that bottom two pair is a strong enough hand to slowplay. I think you're sacrificing a TON of equity by failing to protect your hand with a raise on the flop and again on the turn.

AK of hearts on the turn, for example has 4 J, 3 T, 3 A and 2 K and 8 hearts are all full outs (his hand, KJ, was the same). That's way too many outs for you to be blithely checking behind. Probably the worst part is that after he got a chance to see all his cards and potentially draw out on you, you went ahead and raised.

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-You may not know this, but poker is a game of incomplete information.