For example, when I'm playing a C (3rd fret) on the A string and my next note in the bass line is the G (3rd fret) on the E string - I have often had some trouble jumping strings (eg. from A to E strings) with my first finger without it sounding like a staccato or jilted, especially when I'm playing a faster bass line. Jumping strings any other way in a bass line is fine because I can use a ifferent finger to make that transition and the bassline can flow without missing a beat. But when I have to jump strings with one finger I can't do it too well. It's particularly difficult on a fretless where the finger has to land on a specific spot right above or below the starting string. I hope I'm explaining it clearly.