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.
A play begins with the snap. At the line of scrimmage (the position on the field where the play begins), the quarterback loudly calls out a play in code and the player in front of him, the center, passes, or snaps the ball under his legs to the quarterback.