Playing online poker from the blinds is one of the hardest things you can do when playing cash games. The reason why playing from the blinds is so hard is because you are going to be out of position on every street postflop. The most important factor about playing a hand from the blinds is that you must be ahead of your opponent raising range when you call, and when you 3-bet from the blinds, you must be ahead of there calling range to that 3-bet, or your 3-bet must be effective enough for it to be profitable on its own (IE they will fold to your 3-bet a large percentage of the time).
I have outlined below some of what I would consider standard flatting ranges from the blinds. Obviously no two opponents are the same, so you need to use your common sense. Against players who are playing tighter and not stealing much, you need to be flatting less, against players who are stealing a wider range, you can be flatting a wider range. Likewise, some hands that I generally flat such as ATo and KJo I can sometimes add into my 3-betting range in the right circumstances. All of your actions whether they be fold, call or raise should be based on a sliding scale depending on your opponents ranges.
* add more hands like weaker suited aces,offsuited broadway like QTo KTo and premium suited connectors vs button steals from looser players.
* add hands like suited connectors, suited aces, suited kings and queens vs players with a high fold to 3bet percentage.
Ranges are slightly different vs a button steal and vs a cuttoff open. For example, I may flat a hand as weak as A4s from the big blinds vs a loose opener on the button, I may fold hands as strong as ATo against a tight opener from the button. The key is, to adjust your calling and 3betting frequencies depending on the player. Here are some notes on different dynamics:
Flat less hands from the small blind when you have a aggressive BB who is likely to squeeze. A hand like a7s is almost always a fold from the small blind, but more often a call from the big blind because of this.
The looser the player opening, the looser you can defend. The tighter the opener the less hands you can defend profitably.
You should be defending more to button openers compared to cuttoff openers, because ranges are often a lot wider on the button compared to the cuttoff.
Defending too tight is much less of a leak than defending to wide.
I feel that low pocket pairs have a lot of value and should usually be defended unless the opener is a very good aggressive player.
Against people who have a high fold to 3bet percentage you can add more hands to your 3betting range. However, be warned, in general people defend lighter to 3bets when they are in position compared to being out of position. If you are going to add hands I would consider adding smaller suited aces and suited K’s Q’s and J’s you cant profitably flat preflop.
Against early position raisers hands like KQ AQ and AJ become calls or folds. They are usually not strong enough to 3bet vs that range. Even hands like pocket tens and jacks become a flat preflop to me vs an early position raiser.
Against mid position players hands like KQ AQ AJ can be either a flat or a 3-bet, this is depending on there calling ranges, if they are likely to fold hands like KJ when you 3-bet there mid position open, I would call with it.