Photo Study of the Rafael Nadal Backhand

At the point of contact, Nadal's racquet face is slightly closed (the string bed is facing slightly downward). One might sensibly think that a closed racquet face would send the ball downward too much to get it over the net, but a slightly closed racquet face can lift the ball over the net if the swing creates enough upward friction between the strings and the ball, or if the ball is hit on the rise so that its upward angle of incidence entering the strings is reflected as an upward angle leaving the strings.