Jubber Dubber Doodle

A man who builds a significant lead for himself in a situation that promises to yield beneficial results only to relinquish said lead and finish on the losing end.

I was getting ready to bang yer sister, then I got a softy. I'm such a jubber dubber doodle.

I was playing golf the other day and was down 4 strokes with three holes to go and wound up coming back to beat this jubber dubber doodle.