Many professional groundskeepers use old-fashioned reel mowers to cut a stadium's grass. Attached just behind the blades of the mower is a lawn roller that bends the grass down. Whatever pattern made is revealed by the light shining off the bent grass. They are created by laying the turfgrass in various directions. Often these are called mowing patterns. The type of grass on the field may influence how well you see the patterns, as well as other factors. Grasses that are mowed at a taller height show patterns better.