Fig. 2. Most turfgrass areas are established with hybrid bermudagrasses, which must be propagated vegetatively by sod or sprigs. Sprigs are sections of tillers, stolons, and rhizomes, which can be created by shredding pieces of sod. The sprigs are then spread uniformly, then "crimped" into the soil.
Image from Plant Health Progress article:
Spring Dead Spot of Bermudagrass: A Challenge for Researchers and Turfgrass Managers