评论
打印
American Football
American football is a unique sport-it is a game about gaining territory as much as it is about scoring points. When two teams step onto a football field,each is battling for every inch it can take from the other.Each team wants to defend the field that is behind it and invade the field in front of it. Ultimately,they want to gain enough ground to score a touchdown or field goal.
Ground Rules
Football is a game of inches played on a field measured in yards-English measurements are used to track movements on the field.Teams succeed based on how many yards they accumulate or allow. An official NFL (National Football League) football field is a rectangle that is 120 yards(110 m) long and 53 yards. I foot (49m) wide. Most fields are covered in grass and set in an outdoor (open-air} stadium. Some fields are made of artificial turf, which you'll find in many of the indoor stadiums.
The most essential piece of equipment in a football game is the ball.Official NFL footballs are handmade by Wilson Sporting Goods Co. The football is an oblong (椭圆形的) sphere and has a lengthwise circumference(周线) and a width-wise circumference in the middle of the ball.
With the equipment identified and the field set, we can now play a game.An NFL game is divided into four quarters with an extended halftime break between quarters two and three. Each quarter is 15 minutes long. lf the teams are tied after four quarters of play,they play an additional overtime period of 15 minutes. Inthe overtime, the first team to score wins.
While the game time adds up to one hour, it usually takes three to four hours to play a game. Teams can stop the clock by running out of bounds,throwing an incomplete pass, or calling a time-out, of which they have three per half. Time also stops for each of the two-minute warnings, observed two minutes prior to the end of the second and fourth quarters.
Who's Who
An NFL roster allows for no more than 53 players on a team. At any one time, only 11 players per team are allowed on the field. To understand an NFL roster, you have to identify the three teams within a team: theoffense. the defense and special teams. Each of these groups has specialized positions with a specific setof skills.
Offense
A team's offense is responsible for taking the ball down the field toward its opponent's end zone. To do this. the offense throws the ball from one player to another or holds the ball and runs forward. Here are the basic offensive positions.
Quarterback (QB)-This player throws the ball to receivers or hands it off to running backs. The quarterback is also known as the "field general,"because he's the on-the-field leader.
Offensive linemen-These players provide blocking for the quarterback and running backs. Individual linemanpositions include:
Center (C)-The center is located in the middle of the line. This player hikes the ball to the quarterback by bringing the ball up between his legs.
Guards (LG/RG)-These two players flank the center.
Tackles (LT/RT)-The tackles are positioned on the outside of each guard;teams have two tackles.
Receivers-Receivers run down the field and catch balls thrown by the quarterback. Receivers are either wide receivers (WR) or tight ends (LTE/RTE).depending on where they are positioned on the field.
Running backs-Running backs take the ball from the quarterback and run up the field. Depending on the fomation (arrangement of the offensive players, a running back might be called a tailback (TB), halfback (HB) or fullback (FB).
Defense
When a team does not have possession of the ball, it is on defense and uses various methods to prevent theother team's offense from scoring. These players must tackle the offensive player who has the ball to stopthe offense from advancing.Defense will also try to take the ball away from the offense.
Here are the basic defensive positions:
Defensive linemen-The linemen put pressure on the quarterback by trying to tackle him before he releases the ball. They also try to stop running backs.There are typically three or four defensive linemen.
Linebackers-When there are four linemen, there is a middle linebacker(MLB) and two outside linebackers (OLB). When there are three linemen. there are two inside linebackers (ILB) and two outside linebackers. Their job is to back up the linemen. as well as contain runners and cover receivers on some plays.
Cornerbacks (CB)-The cornerbacks prevent the wide receivers from catching the ball by breaking up passes from the quarterback.
Safeties-The safeties play deep behind the rest of the defense to prevent a long pass or run. A strong safety (SS) lines up on the side of the field where there are more offensive players. The free safety (FS) plays a deep, middle position.
Special Teams
If a team has to kick the ball, it uses its special-teams unit. This unit includes the team's kickers, theoffensive line, and players who run down the field to tackle a returner(see below).
Placekicker-The placekicker kicks the ball through the goalposts to score points and kicks the ball to theother team to start the game and after each scoring possession.
Punter-The punter free-kicks the ball if his team cannot advance the ball down the field.
Returner-During a kickoff or punt, the returner tries to catch the ball and return it as far as he can. A player can score a touchdown on a rcturn.
Moving the Ball and Finding the End Zone
A football game begins with a coin toss to decide which team will receive the opening kickoff. From the opening kickoff, the two teams battle to take possession of the ball. Possession means that a team's offensive unit has the ball.
A team can take possession of the ball in several ways:
Receiving a kickoff-A team receives a kickoff at the beginning of each half and after the other team scores.
Turnover-A team recovers a ball dropped by the other team (fumble)or picks off a ball thrown by the other team's quarterback (interception).
Safety-A player is tackled in his own end zone, meaning the end zone his team is defending, so the other team gets the ball though a free kick.
Punt-The defensive team stops the offensive team from getting 10 yards in three downs, and the offensive team free-kicks, or punts, the ball to the other team on third down.
Turnover on downs-The offensive team fails to advance the ball lO yands in four downs and has to surrenderthe ball to the other team.
For those new to the sport the last two scenarios on this list may not make sense. One of the most confusing concepts of American-style football is the down-and-distance system. Every time a team takes possessionof the ball, it is given a set of four downs, or attempts, to move the ball l0 yards. If the team can movethe ball lO yards or more Within four downs, the team gets another set of four downs to go another l0 yards, and so on. For instance, if a team advances 3 yards on first down, the next play is second down with 7 yards to go (second and 7); if the team then advances 5 yards on second down, the next play is third and 2; if the team then advances 2 or more yards on third down, the next play is back to first and lO, wich a whole new set of four downs during which to advance the ball.
