The Running Back ( RB) is a play position on offense American football. Two different types of running backs are the fullback and halfback. The halfback was frequently referred to in the past as a tailback.

The running back is the primary responsible for the running game players. In contrast to the quarterback who mainly attempts to drive with passes his team forward, the running back takes the ball in his hand and tries to beat a path through the enemy defense. After the snap of the center to the quarterback this passes the ball to the running back, who is the offense in the starting position, the furthest back standing player. Now the running back must first try to get past the defensive line. However, his offensive line helps him ( center, guards, tackles and tight end ( s ) ) to block his way free. After that the running back has to avoid the line backers and safeties. If he succeeds, he creates it into the open field and running into the end zone to score a touchdown. In addition to the running game, running backs, however, can also be used as a pass receiver.

A good running back, first characterized by its speed. The body size, however, is not decisive. There are both small and big running backs. Smaller players tend to have the strength to be able to dodge faster, and can not be so easily getacklet by the enemy, due to reduced attack surface. In contrast, large running backs have the advantage that they can often achieve even one or two extra yards by their mass at the end of a run by powerful throw forward. In addition, they are usually difficult to bring to the floor.

Running backs are also divided in Half Backs and Full Backs. The Halfback is the Agile typical described above or Strong, the fullback, however, is usually more severe and can be used as a security option, as it can gain some yards against set on running game defenses usually. Additionally, running backs for the pass block and as Vorblocker be used.

From a good run test is when he brings about four yards space gain. With four yards per attempt win the running back needs namely no more than the available three attempts, thus reaching a new first down. With regularity but also runs to observe who bring 20 or more yards space gain. In a very good game the running back gets the ball an average of 20 - and 30 - times and gains the mark about 100 yards. The worst thing that can happen to a running back, is that he fumblet. That means he loses the ball before at least one of his knee or his elbow touched the ground. The team that receives the ball has at this point then attack law.

Very rarely, the running back should also take a pass. In such a trick play down trying to lure the enemy on the wrong track. Such a through ball can only occur behind the line of scrimmage, just like the quarterback.

Some of the best known and best running backs of the past and present are LaDainian Tomlinson, Adrian Peterson, Jamal Lewis, Shaun Alexander, Marshall Faulk, Walter Payton, Barry Sanders, OJ Simpson, Corey Dillon, Terrell Davis, Emmitt Smith, Clinton Portis, Jerome Bettis and Chris Johnson.