Pro set

In American football, the pro set or split backs formation is a formation that has been commonly used as a "base" set by professional and amateur teams. The "pro set" formation features an offensive backfield that deploys two running backs aligned side-by-side instead of one in front of the other as in traditional I-formation sets. It was an outgrowth of the three-running-back T-formation, with the third running back (one of the halfbacks) in the T becoming a permanent flanker, now referred to as a wide receiver.

This formation has been particularly popular because teams can both run and pass the football out of it with an equal amount of success. It keeps defenses guessing what type of play the offense will run. Because the backs are opposite each other, it takes the defense longer to read the gap through which the offense will run the ball.^[1]