OK, this is a bit of a rant, and really I love it when opponents make mistakes, but here are a few really common ones that I notice.
- Mass limping allowing the BB a free view of the flop. Of course I love it when I am BB, but when the flop comes JJ3, you may have just allowed BB to play lots of hands like J3 offsuit.
- Setting the limp-call button to automatic. Just recently a player limped with some unplayable hand from early position and I raised all in, and he insta-called indicating that he had set the button to automatically call any raise. I took all his chips, so all was well.
- Making multiple calls of shoves by small stacks, giving them the chance to treble or quadruple up their way out of trouble when it would be better for just one person to take them on, since the objective is to eliminate other stacks until you are in the money, so it usually benefits all members of the herd to pick on the weakest stack.
- Making pointless minraises and min reraises preflop for no apparent purpose. if all the limpers are going to call your raise, it serves no purpose in narrowing the field or knocking out trash cards. If you just want to make the pot bigger so that a half-pot or full-pot bet on the flop will be that much larger, then you need to put in a bigger raise to leverage your hand and hopefully add some dead money to the pot if some limpers fold.
- Limping from SB with trash when it is folded to you. What are you going to do if the flop misses your trash? And if you do make top pair with your Q3 offsuit, what kind of kicker do you have? If you do hit a monster, how do you plan to get paid off If I am the BB and have any kind of hand, I am going to raise the poop out of you, because you are then going to have to play out of position, but in most cases you just fold preflop wasting your chips.
- Miscalculating your outs. If you have an open-ended straight draw, you must take into account the possibility that a couple of your outs could be flush cards for an opponent.
- Miscalculating the odds on flush and straight draws. It is understood that sometimes you are in a desperate position and need a double up right now, but in most cases if opponent with top pair is making a pot-size-plus bet on the flop, calling to go for the flush draw is invalid unless you have additional possible outs like overcards or you have already made second or third pair on the flop, or you also have a gutshot draw. Your odds of hitting your flush on the turn are 9 out of 50, or 18% at best, but if opponents have already mucked flush card suits, they may actually be less.
- Making huge overbets when you have the nuts, and thus failing to get paid off. A player tonight showed me a pair of pocket queens after I folded to his ovebet, but in my view I had morally won the hand in which I had pocket tens, since he did not get paid off.