A stand up stance in football is a stance in which the player is upright and standing instead of on the ground prior to a play beginning. Whether or not a player aligns in stand up stance has everything to do with their position.
The stand up stance has two different variations. Players can either stand up completely straight in a split-legged stance or stand squarely with the knees slightly bent. The former allows players to get a burst of speed off the line of scrimmage while the latter, often referred to as a 'two point stance,' is conducive to quick changes of direction.