Originally posted by YuvalW
According to the starting hand chart if there was a raise in front of you you can call with a small pocket pair according to the call20 rule.
That means that in early position you are allowed to call if your opponent raises, but are not allowed to enter if there was no raise. Why is that? Isn't it worse to call in early position after a raise then it is without a raise?
1st of all, the chart is obviously a simplification... You can't really squeeze all you need to know on good preflop play in a single page... Too many things to consider - exact positions (not just early, middle etc.), your opponents' style, the stacks involved...
The general idea of it is to provide a way of playing that is +EV and solid... even if the optimal EV is higher, reaching it requires playing more situations skillfully in order to not achieve worse results... The chart is supposed to protect the beginner while he adjusts to the game.
The simplification you are referring to is probably due to a couple of simple facts:
If someone raise and you call, you know you have the implied odds if you follow the call 20 rule... If you raise, who's going to call? how many players on the table even have that stack?
That's one thing, another is, the odds of being 3bet when in early position is higher than in any other position (more players to act after you), and when the previous UTG has raised and you call, there is 1 less player to act than if you were UTG (and not UTG + 1).
Finally since in order to get paid you need both to hit AND the opponent will need to hit something too, when you KNOW you have at least one opponent and have other potentials, your implied odds are actually higher quite often, which is important... (set mining likes multi way pots).
To counter all that, the level of play in the micro stakes is generally low enough to be able to play these pairs quite profitably from EP open raise too, and you may decide to do that after you've gained some confidence in your post flop edge over the competition.
Digging at pros' articles/forums/videos etc. I gleaned that technically, over the long run, if you play low pocket pairs from early position regularly and are break even or showing a very small loss, you've done your job as the added pairs to the very tight EP range makes you much harder to read and gets your other hands more profitable.
But that seems to only matter in limits where the opponents actually pay attention to everything you do... which is not the case in the micro stakes. At least not on 0.01/0.02
Hope that partially helps (it's a big topic...)