All the bass teachers say keep the fingers perpendicular to the neck, position the thumb behind the second finger and, gasp, never let it protrude over the top .The problem is the only people who actually teach this are… the teachers. All the great players (with long careers) pretty much ignore it. Paul Macartney is a classic example but I was also watching Tommy Shannon just now - same thing. Fingers and thumb all over the place! The “teacher’s way” is just a sure fire path to injury IMO.
