Well, if we must. First off, using Vaseline on a face was to fill in the grooves to reduce spin. Secoondly, today's modern drivers for the most part do not have grooves in the middle of the face to lessen spin. Yet, t he heel and toe have grooves to help recover off center hits. 15 to 20 years ago, if you recall, some companies were making shiny face golf clubs. This reduced the friction so much, especially when moisture was either on the face or ball it lowered the spin rate so dramatically the ball nosedived into the ground. Bead blasting the face of a Driver created the necessary friction required to maintain proper spin hence groove less faces ala 455 DB. Grooves on irons. I designed the PSi or Progressive Spin irons over 20 years ago. We had an independent lab field test these and they were lab proven to work as designed in conjunction with grooves up to a certain point.