A general question about 4th street

[ddubois]

How large of a mistake would it be to always mindlessly fold 4th street when you've bricked? I intend to include hands, wherein you have otherwise ideal circumstances, into this strategy; for instance, 3 to a straight flush with nearly 0 dead cards, and multiple overcards to your opponent's board, who also happens to be a manaic and might be betting jack high.

Obviously anything that uses the words "always" and "mindlessly" in poker must be wrong, but would it be a very small mistake?