[mike l.]

"A good default line is to bet / fold"

i disagree. i think this is generally a bad play online where the player are more erratic and aggressive.

but i understand and agree with your mixed strategy to an extent. it's basically an extension of sklansky's concept of "game theory". except really that generally applies to total unknown opponents. and then we're back to defaults. which we all agree are wrong.

the game is situational. there are no defaults. there's always a best play and it's oftentimes detectable, and, more often than would seem to be possible, it's counterintuitive as well.

the thing is a mixed strategy works best on the flop and turn and when making a choice between calling or raising. at least that will instill the greatest confusion in your opponents, if that's your thing. if you make a mixed strategy fold the only one who knows about it is you. folds still need to be dictated by pot and implied odds and knowing your opponent.

what if we think about folding (and check-folding) always being the default play in any scenario and street and anything other than that being the entire mixed strategy matrix of possible check-calls, bet-folds, check-raises, call-reraises, etc, etc.