a bit not good

Used in the first episode of BBC's Sherlock, Sherlock says, after asking why a woman would STILL be upset by the death of her daughter, "Not good?". John Watson responds, "A bit not good, yeah."
Later, it became a fanfiction tag, usually on Archive of Our Own, depicting a character in a not very good mental state

Mycroft is A Bit Not Good
"That angst fic had me in tears. Sherlock was a bit not good and John was trying to help him but he was ALSO a bit not good"

your a bit good

When someone fails at doing something the they built up.

jonny scuffed his shot
"Your a bit good " said Henry