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 player on offense who is moving backwards or parallel to the line of scrimmage at the snap. In American football, only one offensive player can be in motion at a time, cannot be moving toward the line of scrimmage at the snap, and may not be a player who is on the line of scrimmage.