Say we open K9o otb, and it is 3b and then capped by BB.

Using the below ranges, K9o has 20% equity, i.e. 1:4 against. But the pot odds are 5:1, so in strict, all-in equity, we should call two to the face. But much of the value of the hand will be post flop -- whether we manage to win more when ahead than we lose when behind. Assuming two competent opponents, my guess is that being in position still makes this a call.

BU 19.97% 19.29% 0.68% { Kd9s }
SB 35.56% 33.67% 1.89% { 77+, A7s+, K9s+, QTs+, JTs, ATo+, KTo+, QJo }
BB 44.47% 42.72% 1.76% { 88+, ATs+, KTs+, QJs, AJo+, KQo }

My first inclination is that your 3-bet and cap ranges are a bit loose given "typical" players...

K9o is a quintessential reverse implied odds hand. I throw it away.

Tightening up, our equity only goes down about 1 point.

BU 18.15% 17.80% 0.35% { Kd9h }
SB 35.70% 33.26% 2.44% { 88+, ATs+, KJs+, AJo+, KQo }
BB 46.15% 43.76% 2.39% { TT+, AJs+, KQs, AQo+ }

I *generally* don't fold a hand here that can make a 2 card straight or flush. But, then again I'm probably opening wider and people are definitely 3 betting me wider in the sb than your ranges. So I can have stuff like K5o, which is the type of hands I fold in this spot, not a hand as strong as K9.

How well do they play post flop?

This hand is on the list of hands that I tend to fold against many people. You make non-nut straights. You're crushingly dominated. If folding this hand is a mistake it can't be a big one. Allowing them to drive you off the bottom of your range is never a big deal.

+1

The other thing is folding when you vpip here wont be exploited by observant players BC you are opening otb and folks are.assuming you're opening wide to begin with so im not worried about a metagame blunder if.you know what i mean. I do understand what dosxx is saying although in my cp 8/16 and even 15/30 unless its short handed k9 would be crushed in this spot.

it seems like this situation comes up so rarely in small stakes games that it's not really going to matter too much what you do pre flop as long as you don't mess it up post flop.

online i wouldn't fold it

live usually not but i guess if both guys are super nits i could see it

10-7 to the flop, yes, rare to be OTB and first to act in a low limit full ring game.

Got me thinking for a bit there.

not only is it rare in ss games for it to fold to the button, but it's also rare that after the button opens the sb and the bb have hands they want to raise with. i can't think of a time where this exact scenario has come up in the games that i play.