By Adam C. Slick
As the mower travels forward, the bedknife pushes against the grass in front of it. At the same time, the reel blade is gathering grass as it moves toward the bedknife. The opposing forces gather the grass together at the shear point. After the grass is cut, it springs back into place—this cutting action produces very small peaks and valleys in the grass. Although indistinguishable by the human eye, these high and low points have a profound effect on ball roll.
Read the full article: A Closer Look at Frequency-of-Clip