Alright, playing in the blinds is one of the most complex topics ever. I am trying to figure this out for myself at the moment, so here is what I can say:
First of all, playing from the CO 2nd worst case (worst case would be a 3bet from the BTN):
You open raise 3x , BTN calls, SB folds. Pot is 7.5bb now and since BB needs to call only 2BB to get 7.5 ( he gets almost 4:1), he calls.
Lets look at ranges:
Your range is wide, but BTN is capped! He would have 3bet AJs+, AQo+, JJ+ and folded junk. BB is super wide since he mostly got in because of the
odds, but he's also capped, since he probably would have 3bet the same range as BTN.
Your situation:
You are playing IP against the BB and you crush his range. Profit for you unless the board is super wet, which favors his range of suited Aces, suited connectors, and small PP's. But he's OOP, so he'll most likely check it to you.
You are playing OOP vs a capped range, which also favors wet board texture. If he bets out on a dry board "cuz everyone checked so imma steal" a x/r
bluff, will do wonders. After all, it should not be too difficult to find the fold, button, too.
Now you're in the SB, which is THE worst position in the game since you are never last to act. There is not a single favorable scenario in this position.
1. BTN raises, you call, BB squeezes. You need to fold.
2. BTN raises, you call, BB folds, you're OOP against the BTN
3. BTN folds, you raise, BB 3bets. You need to fold unless AQo+, JJ+
4. BTN folds, you raise BB calls -> deep trouble here. BB got really good odds and can basically play any2 against you IP. Good luck putting him on a range on a J73 doublesuited board once he calls.
Playing from the SB is basically 3bet or fold in 6Max. If you call a raise from the BTN, BB is getting uber odds and can squeeze.
When it comes to your situation, meaning opening the pot from the SB, I see most people do the same mistake: They don't raise big enough and they ply too wide...cause what can he have, right?
Just do the math. A 2x raise will give him over 3:1, a 3x raise will give him over 2:1, so he's incentivised to call rather wide while the only thing you want in this situation with your J9o is a fold. So crap vs. crap, while odds are against you...not so good.
So the only thing that makes sense is playing tighter when opening from the SB. A2s+, 77+, ATo+. Since you play tighter, you need to raise big enough to destroy his odds, which basically means a 3.5-4x raise.
And that's why every
equity calculator will give you a pretty tight range for the SB.