60% of all the grass on putting greens today did not exist 30 years ago and as a result the mow height on greens is 50% lower than it was 20 years ago. Greens are much faster than they used to be.Faster green means shorter grass and shorter grass means there is no longer the need for 4 degrees of loft (the traditional loft) on putters. Most PGA Tour golfers have an effective loft of somewhere between 1 and 3 degrees. This means that when they add the loft on the putter face to the amount of loft they add during the stroke it comes out to somewhere between 1 and 3 degrees. Consequently very little flight time and early roll mean less bounce and skid - a good thing! Zach Johnson actually has -1 degree of loft on his putter face. Speaking of early roll - grooved face putters get the ball rolling 18-24% sooner than smooth faced putters. Not only that, they deter the ball from sliding up or across the face on poorly struck putts too. Sign me up for some of that help.