Book 1 – Ch.3 – Pg.14
Sincerely: The trick to writing Jack has always been to remember that he’s actually very smart but he’s also at least somewhat drunk pretty much all the time. Does it matter that a delicatessen is a place, not a profession? No. Does it matter that cakes are not generally made in a delicatessen? Also no.
I always described Jack’s role from the team perspective as “loose cannon”.
Turns out the term also fits with your description of his character as a person – always somewhat drunk and very smart.
Rolling around uncontrollable is one part of it, being heavy enough to produce considerable, well, impact, on impact, is the other.