pics work for me on laptop and phone. sabatini.
i don't know any men offhand that have an extreme grip for a 1hbh. maybe there are but i don't know any. All the top 1hbh guys with the super spin and pace have an eastern grip or less. Maybe Almagro is approaching extreme but i wldn't call his grip extreme. And he changes his grip. Sometimes he uses an eastern and sometimes his knuckle is on the edge.
here he is with an eastern. knuckle squarely on the top bevel. this is the standard eastern backhand grip. not extreme.