SNP genotyping is the measurement of genetic variations of single nucleotide polymorphisms (SNPs) between members of a species. It is a form of genotyping, which is the measurement of more general genetic variation.
On most plays, the center will snap the ball directly into the quarterback's hands. In a shotgun formation, the center snaps the ball to the quarterback lined up several yards behind him.
That frees up the inside linebackers and allows them to run to the football while the two outside linebackers (the premium position in the 3-4) make plays as edge defenders out of a stand-up, two-point stance.