Changes in Offensive Holding

• Prior to the mid-1970s, offensive linemen could not put their hands on defensive linemen while blocking. When pass blocking, their hands had to be tight to their uniform shirts and the only weapons they had at their disposal when it came to blocking were their shoulders, forearms and bodies. Put your hands on a defensive lineman or a linebacker and it was a 15-yard penalty. That changed when league officials decided that defensive linemen and linebackers who rushed the passer had too much of an advantage. Not only could a defensive lineman use his hands to shove the blocker aside, he could use his hands as clubs to bash offensive linemen in the head. After watching Los Angeles Ram defensive end David "Deacon" Jones use the head slap as his primary weapon for tormenting opposing linemen on his way to the quarterback, officials finally decided to let offensive linemen use their hands to "punch" defenders in order to keep them away from the quarterback or the running back. The hands must stay within the frame of the body--an offensive lineman can't reach outside to grab and throw a tackler, but he can deliver a heavy blow in order to do his job better. In addition to relaxing the holding call, the penalty has been reduced from 15 to 10 yards.
  
  

Protecting the Quarterback

• One of the biggest rule changes in the NFL has been the decision to protect the quarterback from aggressive contact. While one of the primary aspects of playing great defense is pressuring the quarterback and sacking him before he can throw, the defender cannot hit the quarterback in the head, he cannot lead with his own helmet and he can't hit the quarterback after he has released the ball. If an onrushing defensive lineman does not alter his direction after the quarterback has thrown the ball and runs into the quarterback, he will get a 15-yard roughing-the-quarterback penalty called against him. The hit delivered by the defender does not have to be a vicious one in order to earn a penalty call. A blow that comes a second or more after the quarterback has thrown the ball will result in a penalty.
  
  

Instant Replay

• The NFL experimented with instant replay for several years on an "experimental" basis before abandoning it for several years and then deciding to make it a part of the game's landscape. On plays where possession, down-and-distance and scoring are at issue, a coach may challenge the on-field ruling and send the referee to the video-replay area to review the play. For example, a receiver may be credited with a catch along the sidelines that resulted in a 35-yard gain. However, the coach of the defending team may think the receiver did not get both of his feet down inbounds while he possessed the ball. He can throw a red challenge flag on the field and to signal the initiation of a review. The referee then watches a replay and decides whether there is sufficient video evidence to overturn the play. If there is not, the call on the field is upheld. If there is, the pass is ruled incomplete and the ball goes back to the previous line of scrimmage for the next play.
  
  

Goalposts

• Field goal kickers continue to play a huge role in the NFL, because there are nearly as many field goals ever year as there are touchdowns. However, it was much easier to kick a field goal through the 1973 season. Through that year, the goalpost was placed on the goalline. In the 1974 season, the goalposts were moved 10 yards to the back line of the endzone. This was done to encourage teams to go for touchdowns and make it tougher to kick the field goal.
  
  

Overtime

• The NFL initiated regular-season overtime at the start of the 1974 season in order to have more games played to a decision and discourage tie games. The regular-season overtime consists of one 15-minute quarter that ends when a team scores a touchdown, field goal or safety. As a result, losing the coin toss at the start of overtime can be a huge disadvantage because the team kicking off may fail to even get a chance with the ball if the opponent scores on its opening possession.