In fantasy football, the Flex position is an extra roster spot in the starting lineup that allows a fantasy manager to play an extra running back, wide receiver, or tight end. The Flex position is a feature that gives the fantasy football manager the flexibility to build a competitive squad to compete. Most leagues will allow one or two Flex spots, and the players that are allowed to be started in the Flex position vary from league to league. The top Flex players in fantasy football are usually the players that rack up the most points from the running back and wide receiver positions. The Flex position can be the player that gives a team that extra boost to win a matchup or be the reason that the fantasy team loses by a couple of points.