This is one of my favorite dahlias. It's a dark red ball introduced by Cor Geerling (Holland) in 1994. His wifes name is Nel (really).
It is currently listed as a Ball Type, but previously I think it was listed as a Formal Decorative.
Popular in the Dahlia shows, has ~2000 awards.
I have been growing it since 2007. It grows well here in Michigan.