Running Back A running back ( RB ) is the position of a player on an American or Canadian football team who usually lines up in the offensive backfield . The primary roles of a running back are to receive handoffs from the quarterback for a rushing play , to catch passes from out of the backfield , and to block . There are usually one or two running backs on the field for a given play , depending on the offensive formation . A running back may be a halfback ( HB for short , in certain contexts also referred to as a tailback ) or a fullback ( FB ) . Halfback / tailback . The halfback or tailback position is one of the more glamorous positions on the field , as it is often integral in both the passing and running attack . A well - rounded halfback is commonly viewed as a requirement for a team ' s success . He is responsible for carrying the ball on the majority of running plays , and may frequently be used as a receiver on short passing plays . In today ' s game , an effective halfback must have a superior blend of both quickness and agility as a runner , as well as sure hands and shrewd vision upfield as a receiver . More and more quarterbacks depend on halfbacks as a dump - off receiver when primary targets downfield are covered . Occasionally , they line up as additional wide receiver s . When not serving either of these functions , the primary responsibility of a halfback is to aid the offensive linemen in blocking , either to protect the quarterback or another player carrying the football . On some rare occasions , running backs are used to pass the ball on a halfback option play or halfback pass . No position in Canadian / American football can perform his duties successfully without the help of other players . Like the wide receiver , who generally cannot make big plays without the quarterback passing to him ( with the exception of the end - around or a reverse ) , the running back nearly always needs good blocking from the offensive line to successfully gain yardage . Also , a running back will generally have more rushing attempts than a receiver will have receptions , which is mainly because a receiver must catch a pass to obtain a reception , while a running back usually takes a direct handoff or short pitch from the quarterback before registering a rushing attempt . Note that the difference between halfback and tailback is simply the position of the player in the team ' s offensive formation . The halfback lines up approximately half - way between the line of scrimmage and the fullback ( similarly , quarterbacks line up a quarter of the distance between the line of scrimmage and the fullback ) . Because the halfback is usually the team ' s main ball carrier ( while the fullback is primarily a blocker ) , many coaches see fit to position the halfback behind the fullback ( at the " tail end " of the formation ) . In this case , the halfback becomes a tailback . Fullback . In most college and professional football schemes , fullback s carry the ball infrequently . Currently , they are primarily used to aid the offensive linemen in blocking . On most running plays , the fullback leads the halfback , attempting to block potential tacklers before they reach the ball carrier . Fullbacks are sometimes used in passing plays , although they typically protect the quarterback . Fullbacks are technically running backs , but today the term " running back " is usually used in referring to the halfback or tailback . Although fullbacks currently are rarely used as ball carriers , there was once a time when they ran the ball as frequently as running backs . In high school football , where the offenses are simpler and player sizes vary greatly , fullbacks are still frequently used as ball carriers . In high school football and sometimes in college football , a scheme known as the " Triple Option " utilizes the fullback as a ball carrier . The fullback is considered a primary ball carrier in this scheme and plays a unique role by establishing an inside running threat . Triple Option scheme fullbacks require excellent ball carrying skills and employ a tenacious running style , but often lack the receiving skills of their counterparts in other schemes . College teams such as Navy and Air Force have employed the triple option scheme with success . While in years past the fullback lined up on the field for almost every offensive play , teams often opt to replace the fullback with an additional wide receiver or a tight end in modern football . Fullbacks in the National Football League rarely get to carry or catch the ball since they are used almost exclusively as blockers . Their talent and value to a team is usually judged by the success of the team ' s halfback or by how many times the team ' s quarterback is sacked , similar to the way offensive linemen are judged . Fullbacks are also still used occasionally as rushers on plays when a short gain is needed for a first - down or touchdown , as they are large and powerful and therefore effective at breaking through the line for a short distance . Jim Brown , Marion Motley , Franco Harris , and Larry Csonka were great fullbacks and some of the pioneers . More modern examples include Mike Alstott and Tony Richardson . Characteristics of a running back . Height and weight . There is a great diversity in those who play at the running back position . At one extreme are smaller , faster players . These fast , agile , and elusive running backs are often called " scat backs " because their low center of gravity and maneuverability allow them to dodge tacklers . Prototypical " scat backs " would be Barry Sanders and Emmitt Smith . At the other extreme are " power backs " : bigger , stronger players who can break through tackles using brute strength and raw power . They are usually ( but not always ) slower runners compared to other backs , and typically run straight ahead ( or " North - and - South " in football terminology ) rather than dodging to the outside edges of the playing field ( i . e . running " East - and - West " ) like shorter , quicker , lighter backs will often do . Jim Brown , John Riggins and Earl Campbell can be considered typical " power backs " , Brandon Jacobs , Steven Jackson and Peyton Hillis are more recent examples . Receiving ability . Over the years , NFL running backs have been used more and more as receivers out of the backfield , especially with the rise in popularity of the West Coast offense and its variants . On passing plays , a running back will often run a " safe route , " such as a hook , that gives a quarterback a target when all other receivers are covered . Two backs , fullback Larry Centers and halfback Marshall Faulk , rank among the NFL ' s top 20 pass catchers . Some teams have a " third down back " , who is skilled at catching passes or better at pass blocking and " picking up the blitz , " and thus is often put in the game on third down and long . He can also be used to fool the defense by making them think he is being put into the game for a pass play , when the play is actually a run . Blocking . Running backs are also required to help the offensive line in passing situations , and , in the case of the full back , running plays . Running backs will often block blitzing linebackers or safeties on passing plays when the offensive line is occupied with the defensive linemen . On running plays , the fullback will often attempt to tear a hole in the offensive line for the running back to run through . Effective blocking backs are usually key components for a running back ' s success . On passing plays , a running back will stay back to help block and pick up the blitz . Goal line backs . Many teams also have a running back designated as a " goal line back " or " short yardage specialist " . This running back comes into the game in short yardage situations when the offense needs only a little bit of yardage to get a first down or a touchdown . They also come into the game when the offense nears the goal - line . Normally when an offense gets inside the 5 yard line they send in their goal - line formation which usually includes 8 blockers , a quarterback , a running back , and a fullback . The closer they are to the goal - line the more likely they are to use this formation . If a certain running back is used often near the goal - line he is called the goal - line back . Short yardage and goal - line backs often are Power Backs that are not prone to fumbling . Their job is to get the first down or touchdown by muscling through or pushing a large mass of defenders to push their way to the designated area . Kick and punt returners . Running backs are sometimes called upon to return punt s and kickoff s , a role usually filled by wide receiver s and defensive back s , such as cornerbacks , who are generally the fastest players on the team . A running back , Brian Mitchell , holds the NFL records for kickoff return yards ( 14 , 014 yards ) and punt return yards ( 4 , 999 ) . ( Mitchell also gained 1 , 967 rushing yards , 2 , 336 receiving yards , and 14 fumble return yards , giving him a total of 23 , 330 all - purpose yards , the second - most in NFL history behind Jerry Rice . )