Isn't it great what you find lurking in the depths of your computer?

[thereallyniceman]

This is all you need to know to play Classic Banjo  ;-)

[IAN SALTER]

The use of the left thumb to sometimes stop the 4th string, is mentioned on page 8 of Briggs' Banjo Instructor. However, I couldn't find any specific examples of this in any of the tunes. I haven't checked if this technique was mentioned in the tutor books that came after Briggs'. I used it all the time on my tackhead to stop the 4th string at the 2nd fret.

Joel Hooks said:

So is the "support the neck in the hollow" the same as what I call a baseball bat grip with thumb over the top?  Many plectrum guitarists (steel string Spanish guitar played with a pick) do this to stop/fret strings with their thumb over the top I think.  I also see this with bluegrass banjoists, old time banjoists, and classic banjoists who are either "by ear" self taught or came from BG or OT first. 

When I watch them play I can't help but notice that they are constantly shifting and tilting their wrist when they need to chord or play something more than just a monophonic string of notes.  Or they fight the awkward position and fumble through.