i always considered blind defense something you do only when someone in LP or SB raises to steal the blinds. ideally you want to get HU with the thief and outflop him/outplay him postflop. you only do it because it's often a cointoss who will hit the flop and your pot odds are favorable HU.

if the pot is multiway, i'm not defending the blinds without a legitimately strong hand or some kind of weird draw that's getting really good pot odds.

ChezJ