Post by Coach Campbell on Feb 8, 2009 12:44:29 GMT
The American football is a collective Sport in which the purpose of two teams are to carry the balloon to an unfavourable zone at the end of the ground. When a player penetrates in the zone of in-goal in possession of the balloon, it is said that it registers a “Touchdown” (English term included such as it is in the majority of the French-speaking country) or than it does one “touched” (Quebec).
History
American football goes down from the Football and the Rugby. These two disciplines codified in England are introduced in North America as of 1861 for football and in 1864 or 1865 for Rugby. The first match of Rugby played on the American continent is probably disputed in 1864 with Toronto or in 1865 with Montreal. This Canadian branch will give rise to the Canadian Football.
With the the United States, the university teams practice also Rugby and football. It is the occasion of confusions besides. Thus, for a long time, it was considered that the first American football game was held the November 6th 1869: Rutgers is essential 6-4 vis-a-vis the College off New Jersey (future Princeton). According to research of the historian Stephen Fox, this match of New York Ball could be a match of Football. Princeton and NFL admits from now on this version.
The Canadians propose to the Americans a university match of Rugby opposing Montréalais of the Université McGill to the students of Harvard, who did not practice football at all. One plays one half-time according to the rules of each university. Indeed, each school has its own payments, as that was also the case in Europe a few years earlier. Harvard adopts in 1875 like payment that enacted by Yale, but it is always about a mixture between Rugby and football, named “combination” in Europe. It is necessary to await the November 23rd 1876, and famous “the Massasoit convention”, to see the installation of common rules at several American universities. In fact, they adopt the whole of the payments of the English federation of Rugby except for a detail, the counting of the points. American football clearly different from its ancestors still remains to be created.
Between 1880 and 1883, Walter Camp, trainer of Yale, modifies in-depth the rules and the spirit of the play: reduction of the players from 15 to 11, reduction of the surface of the ground and introduction of the scrimmage. These modifications of Walter Camp are supplemented by others at the same period: a team must return the ball to the adversary if she did not manage to progress of five yards in three attempts. American football was born.
The first professional players are listed in 1892 - 1893, but it is necessary to await 1896 to see the first team made up exclusively of professional players: “Alleghany Athletic Association”. One year later, “Latrobe Athletic Association” is the first team to buckle one complete season with a formation made up exclusively of professional players (1897).
The first supplemented master key date of the October 27th 1906. Before this date, the master keys ahead were not authorized.
The National Football League (NFL) is set up in 1920 in order to put a term at the underhand dealings which reign then in the world of American football.
American football remains a long time confined in the only United States where it becomes the sport number one, in front of the Baseball, as of the Années 1970. Notable exception, the Japan, influence American obliges, where a university championship since 1947 disputes. The play is introduced in Europe between the end of the Années 1970 and the beginning of the Années 1980. A International federation of American football is created in 1998.
Play
The rules such as they are presented here correspond to those of the American professional championship (NFL). They differ sometimes appreciably according to the competitions. In Europe, American football is practiced thus while being inspired rather by the rules in force in the American university championship of NCAA.
Ground and equipment
The ground
The ground measures 100 Yard S length, that is to say 91,44 m, divided into portions 10 yards. With the center of the ground of the hatched features ( hashmarks ) all the yards for the same reason are laid out longitudinally. These hashmarks delimits the maximum width authorized for the settings concerned in order to prevent that these last proceed too much close to the touchlines. At each end one finds the zone of in-goal called endzone and, at the bottom of this one, the posts between which the balloon must pass for the boot of transformation (after a touchdown) or the boot of placement ( field goal ).
Equipment
The multiplication of the accidents often mortals at the end of XIXe and the beginning of the XXe century, pushed the authorities to make protections obligatory on the level amateur. Each player carries a helmet, épaulières, one protects teeth and from protections on the thighs, the hips, the coccyx, like on the knees. These protections are optional at the professionals. Certain players wear gloves specific to their station. For example, a player of line (“lineman”) will have gloves reinforced with the articulations and on the top of the hand, and a Wide receiver (distant receiver) will have finer gloves with a better adherence for better collecting the ball. One needs also good shoes of American football (shoes for cramps; moulded or screwed cramps). The grids of the helmets are different according to the occupied stations. It is more open for the Quarterback S and receivers who need to have a good vision of the play; they are tighter for the players of line.
The balloon is of form oval and includes/understands a lace allowing the best taken in hand by the quarterback.
Course of the play
Duration
The part lasts 60 minutes effective - but several hours on the whole - and comprises four 15 minutes quarter-times. Between the two first (and the two last ones) quarter-time, one just carries out a change of with dimensions and one keeps the same relative position for the balloon. On the other hand, between 2nd and the 3rd quarter-time, it is the half-time with rest. At the beginning of the 3rd quarter-time the team which received engagement engages in her turn. In the event of equality, a prolongation is exploited the mode of “sudden death”.
Phases of play
An American football game proceeds in two quite distinct phases of play: the attack and defense. The change between the two phases takes place on several occasions detailed low.
The play starts with a boot of engagement or kickoff . This kick is used starts each beginning of period of it (half-time) or to take again the play after a team marked points. It is, in the majority of the case, used to further send the balloon possible in the opposing side. A player of the opposing team must catch up with the balloon and try to advance balloon in hand. The place where the player going up the balloon will be plated will determine the place where the phase of attack will begin for its team.
The team having the balloon is in phase of attack and has four attempts to traverse 10 rods (yards). Once the progression of 10 rods carried out, the team has four new attempts to progress again of 10 additional yards and so on. This is why it is said sometimes that American football is a play of " gain-terrain". If, at the conclusion of the four attempts, the team did not traverse this distance, the possession of the balloon is given to the adversary. The adversary recovers the balloon at the place then where the attack stopped: it is a turnover one downs . To avoid that the opposing team does not recover the balloon too much close to the zone of in-goal and is thus in a situation to mark too favorable, it is possible to type a kick (generally carried out at the time of the fourth attempt) in order to release the balloon. This kick of release is called boot of release. ( punt ).
In phase of attack two means of progression can be used:
the race: In this mode of play the balloon passed directly in person by theback one (Quarterback) to another player called half to the attack ( Running back ). This one must then run with the balloon by avoiding the unfavourable defenders. There exist many alternatives of this type of attack, theback one can for example run with the balloon without making of master key or can transmit it to the running back by the means of a short master key. (It is important to mention that theback one (Quarterback) does not have any more the right to launch the balloon towards the unfavourable zone of in-goal, (passes ahead) at once that it crosses the line of fray ( line off scrimmage ).)
the master key ahead: The quarter-back lance a master key with one of its receivers who will be, au préalable, moved on the ground while following a well defined trajectory. This trajectory, known in advance of the two players, allows, in addition to synchronization between frontier runner and receiver, to destabilize defense by using atypical trajectories. Once the balloon caught by the receiver, this one can continue to run balloon in hand. So that a master key is valid the balloon must be caught without it touching the ground by a player having his two feet inside the limits of the ground. If it is not the case the master key is known as incomplete .
In both cases the whole of the team can carry out blocks in order to protect the players carrying the balloon (quarter-back, runner or receiver). The blocks must be only carried out by pushing the adversary without plating it or holding it.
In phase of defense several methods can be employed to stop the progression of the balloon:
the plating: The goal of the plating is to put on the ground the carrier of the balloon. The play stops as soon as the carrier of the balloon is on the ground, the next attempt at attack will begin at the place where the player was plated. Only a player carrying the balloon can be plated. A plating carried out on theback one is called Sack (If the plating takes place in the zone of in-goal, that brings back 2 points to the defensive team, the safety ). If the plated player loses the balloon, the balloon can be recovered by one of the two teams. This particular event, being able to give place to an inversion ( turnover ) if defense recovers the balloon, is called fumble . (If a player is plated inside the ground, the stop watch continues. If it leaves or is thorough touches some, the stop watch stops. That with a very important impact on the strategy of the play, in attack.)
the interception: It takes place when a defender intercepts a master key intended for a receiver. The defender having carried out the interception can progress balloon in hand until it is plated. Its team will then begin her phase from attack at the place where the plating took place.
To mark points
There exist several manners of marking points:
the test, touched or Touchdown is worth 6 points. It takes place when a player is in possession of the balloon inside the zone of in-goal of the opposing team. It is enough that the ball passes the line of the zone of in-goal so that the touchdown is valid on a play of race or that a player receives the ball in the zone with 1 or 2 feet on the ground according to the championship.
a touchdown gives place to an attempt at transformation, or a conversion. This attempt, played with 2 or 3 yards (2 in NFL) of the line of in-goal can be carried out in two manners:
By striking a kick the same model as the field goal . This type of transformation, called extra point , is worth 1 point.
By marking the equivalent of a touchdown. This type of transformation, called two-point conversion , is worth 2 points. This type of transformation is much more difficult to mark than a kick and thus is generally used only in particular cases where the team must quickly mark points.
the boot of placement or field goal is worth 3 points. A kick to be validated must pass between the two vertical bars of the goal. If the kick is missed, the possession of the ball is given to the opposing team at the place where the kick was struck.
the touched safety or safety is worth 2 points. One touched of safety occurs in the zone of in-goal of the team being in possession of the balloon. It is granted if the carrier of the balloon is plated in its own zone of in-goal or leaves the limits of this one or if a fault of attack is made in this zone.
Faults and penalties
With American football, the penalties are almost never individual, they sanction the whole of the team by a loss yards (5 yards, 10 yards, etc) and/or attempt. The penalties are announced by flags (yellow handkerchief) that one of the seven referees throws by ground when he sees a fault, the principal referee, the referee (recognizable with its white cap), communicates then by gestures with the players and the public to indicate the nature of the fault and consequently the number lost yards. The most current faults are the early retirements, the illegal contacts (in the back for example. Also called illegal block), the seizure of the grid of the helmet ( facemask ) and obstructs it of master key ( not interference ).
Composition of the team
Although there are only 11 players of each camp on the ground during each phase of play, a team comprises a great number of players. The roster (effective) comprises 53 players. The replacements are not limited as in the majority of the other sports but can be carried out between each phase of play. A football team American account thus several specialized formations adapted to the various phases of play. These formations are made up different players although some can belong to several units.
Defense
The team installation in defense can be divided into three principal curtains:
First curtain: This curtain made up of the players of defensive line. Defensive end > (D-end) or defensive wingers and of Defensive tackle defensive (D-T) or platers. This curtain has for double objective to stop the races and to prevent theback one from passing the balloon.
Second curtain: The role of this curtain of defense, evolving/moving between the long and short lines of defense, is mixed. The players of this line called Linebacker or secondeurs must indeed compensate the first line by stopping the races and the third line while intervening on the master keys.
Third curtain: Defensive backs ( defensive backs ). Their role is to thwart the play of master key of the adversary. The players belonging to this curtain are Cornerback S or halves of corner and safeties or petty thieves, the latter acting as ultimate defenders.
The attack
It is made up:
of a Quarterback (QB, also called quarter-back with the Canada) which is that which directs the offensive and calls the plays. It is the first player with touching with the balloon, after the center. It is connected with a half of opening to Rugby, it must have a good vision of the play, an excellent leadership, as well as calm and a coolness with any test. (Contrary to the popular belief, quarter-back the is not the only player authorized to make a master key ahead. All the players can do it, except the center, as long as they do not cross the line of fray.)
of carriers of balloon (Running back S): rapids and powerful, their goal is to cross the unfavourable defensive curtain. There is half-back (HB) very fast, it is connected with a three-quarter centers with Rugby, and the fullback (FB) more powerful but slower in rule general than the halfback, he is also used like cleaner of defense in front of the halfback.
of the distant wingers (Wide receiver S) (WR) (receiver) very fast, nimble and skilful (like a three-quarter wing of Rugby). Legs of sprinter and hands of basketball player, it must receive the long master keys of quarter-back and traverse a maximum of distance balloon in hand (yards after receiving).
of the brought closer wingers (Tight end S) (TE), large, powerful and fast players (3rd line of Rugby), they are very general-purpose and can moult themselves as a receiver as out of blocker.
of five men of offensive line (Offensive Linemen) (OL), imposing workers of the shade who protect theback one from the defenders who could threaten it, and who open breaches in defense for the carriers of ball. One of them, the center, has as an additional function to transmit the balloon to the back quarter at the beginning each phase of play (it is the snap ). The offensive line is subjugated with particular rules which restrict their placement, their classification, as well as the possibility for them of taking delivery of a front master key. It is extremely rare to see one to carry the ball to between-them. They are capital players for the good performance of an attack, but they are generally ignored of the public. This line is composed of the center, the Offensive tackle S and the Offensive guard S.
Special units
These units come into play at the time of quite specific situations. There exist different formations to carry out the boots of engagement, of release as well as the placements (boots of three points or field goals ). Certain specialized ultra players enter on the ground only for these phases of play. It is in particular of the punter which carry out the boots of release, of the kicker, specialized in the kicks placed (transformations and field goals ) and about the Long snapper which replaces the center in some of these phases of play. A special TEAM defensive is also installation at the time of each one of these situations. They act to prevent the opposing team from marking or to go up the balloon most effectively possible in the case of a boot of engagement or release.
Strategies and tactics
The character extrèmement hâché of the play, the principle of the gain-ground and the replacements unlimited led, with the passing of years, the trainers to develop tactical diagrams of a great sophistication. The development of the video analysis and data processing still accentuated this phenomenon. American football is often compared with a form of set of failures whose parts would be alive, and many subtleties escape the spectator even informed.
Strategic philosophies
To build what they call them system , the trainers are brought to make choices on their offensive, defensive priorities and on the special teams. Is it necessary to privilege the possession of the balloon, or to play with the position on the ground? In attack, will one use the play of front master key to release then from spaces for the race, or on the contrary the play it will be based on plays on the ground with from time to time of the pretenses leading to master keys before ( play-action )? In defense, one can choose a risky system but being able to pay large consisting in sending additional defenders to put the pressure on the Quarterback ( blitz ), or one can decide to let the adversary gain gradually ground without conceding broad portions of them, by counting on the fact that it will end up making an error ( the reed folds but does not break ). Finally choices also are essential as for the special units. When is it necessary to release in 4th attempt, when is necessary it to try the whole for the whole?
Offensive formations
The rule of American football imposes that seven players at least are positioned just behind the line of scrimmage . The others must be in withdrawal of at least a rod (1 yard), positioned in the back-field . It is not without tactical consequences because only the latter as well as the players located at the ends of the line are authorized to take delivery of a front master key. According to the system of offensive play, the trainer will thus position the players in order to optimize the result.
Offensive tactics of play
One coarsely distinguishes three ways of doing advance the balloon on the ground ( play of race ): in power (by using the force of the carriers of ball and the offensive line), in speed (while playing so quickly that the second curtain does not have time to react) or in smoothness (by hiding the balloon, by multiplying the pretenses or by playing the option ). In the same way, there exist several types of master keys before: most traditional is the drop back which sees the QB moving back of some steps while looking in front of him (it reads defense) before stopping and to launch its master key. The men of line then form a pocket to protect it. The QB can also leave directly towards outside ( roll out ), it becomes more threatening for defense since it can decide to pass or to run itself. This tactic of play is particularly effective when it is combined with a pretense of race on the other hand ( bootleg ). The disadvantages for the attack are that the precision of the QB is less since it runs, it is exposed more to defense, and it cannot exploit the entirety of the ground any more because a master key “across the ground” would be hazardous.
Lastly, another category of master key is particularly effective against aggressive defenses, it acts of the screen not . In this type of master key, the QB moves back exaggeratedly while the offensive line lets penetrate the defenders and is placed in front of a receiver or a carrier of ball which will have been dissociated. Right before being made sacker , the QB passes the balloon to the receiver who has a genuine screen ( screen ) of protection to progress.
Coding of the formations
The choice of the tactics is dictated in Quarterback by the coach. Then at the time of the huddle i.e. the gathering of the players before the sequence of play, this one gives code name corresponding to the tactic to carry out. At the time of the calculation, the quarterback can still change the tactics into shouting a new code name ( Audible ). Each code name corresponds to a combination worked with the drive by the players. All the formations are recorded in a playbook .
Defensive formations
The placement in defense is free. The defensive formations most current in NFL are the 43 (4 men of line, 3 linebackers and 4 backs) and the 34 (3 men of line, 4 linebackers and 4 backs). Because of great number of master keys before tried in this championship, one frequently replaces players of the first and second curtain by one ( nickel ) even two ( dime ) back defensive additional.
Defensive tactics of play
Among the tactical choices that the trainer of defense must make, there is that of the mode of cover of master key: zone or individual. The defense of zone is less likely to concede broad portions of ground of only one blow. It gives greater chances to the defensive backs to intercept the balloon, but it requires intelligent and disciplined defenders. Individual defense requires more athletic players, it generates less incomplete interceptions but more master keys. It offers also more possibilities as for sending defenders blitzer . Several play are possible in defense like the flex , the standard , the not defense , etc
Management of the stop watch
The stop watch stops when a master key is incomplete , that the carrier of the balloon leaves the ground, after an idle period, a fault, etc and it continues when a player is plated. This adds a dimension enthralling to football: a team which leads to the score and which with the ball in its possession may find it beneficial to play the watch, and to use 45 the second available ones before each setting concerned to make waste time. Under these conditions, the match can thus be finished 2 minutes before the official end if the adversary does not have any more idle periods: theback one (Quarterback) will be satisfied to put a knee on the ground (even consequence that a plating thus not of stopping of the stop watch) and this for its four attempts . In the same way, a team in possession of the balloon, led to the score at the end of the match, will multiply the master keys, and its carriers of ball will make very to leave in key in order to stop the stop watch. A quarterback will be able to even throw the ball on the ground voluntarily, sacrificing an attempt.
Physical qualities
American football is a sport diversified enough in terms of gauges. This sport privileges the powerful gauges and very rapids but one needs also imposing gauges to form the lines or average or smaller gauges for the running back and wide receiver. The Quarterback requires an agility and a vision of the play above all but it must be also solid to avoid the wounds.
In NFL the players are authentic athletes: the majority of the receivers are large sprinters of which some of them come very close to 10 seconds with the 100 meters. They are able to traverse 60 yards of grounds in a few seconds (with the equipment) to turn the head and to collect balls launched out of missiles then to survive the plating of the defenders. It is one of the most impressive sports at the athletic level with players who spend twice more time in room of musculation than on the ground.
It should however be specified that this sport, such as it is applied to the the United States at the professional level, often is quoted like one the most touched of by doping; thus it is explained that the life expectancy of a professional player of American football did not exceed 55 years in the Années 1990.
History
American football goes down from the Football and the Rugby. These two disciplines codified in England are introduced in North America as of 1861 for football and in 1864 or 1865 for Rugby. The first match of Rugby played on the American continent is probably disputed in 1864 with Toronto or in 1865 with Montreal. This Canadian branch will give rise to the Canadian Football.
With the the United States, the university teams practice also Rugby and football. It is the occasion of confusions besides. Thus, for a long time, it was considered that the first American football game was held the November 6th 1869: Rutgers is essential 6-4 vis-a-vis the College off New Jersey (future Princeton). According to research of the historian Stephen Fox, this match of New York Ball could be a match of Football. Princeton and NFL admits from now on this version.
The Canadians propose to the Americans a university match of Rugby opposing Montréalais of the Université McGill to the students of Harvard, who did not practice football at all. One plays one half-time according to the rules of each university. Indeed, each school has its own payments, as that was also the case in Europe a few years earlier. Harvard adopts in 1875 like payment that enacted by Yale, but it is always about a mixture between Rugby and football, named “combination” in Europe. It is necessary to await the November 23rd 1876, and famous “the Massasoit convention”, to see the installation of common rules at several American universities. In fact, they adopt the whole of the payments of the English federation of Rugby except for a detail, the counting of the points. American football clearly different from its ancestors still remains to be created.
Between 1880 and 1883, Walter Camp, trainer of Yale, modifies in-depth the rules and the spirit of the play: reduction of the players from 15 to 11, reduction of the surface of the ground and introduction of the scrimmage. These modifications of Walter Camp are supplemented by others at the same period: a team must return the ball to the adversary if she did not manage to progress of five yards in three attempts. American football was born.
The first professional players are listed in 1892 - 1893, but it is necessary to await 1896 to see the first team made up exclusively of professional players: “Alleghany Athletic Association”. One year later, “Latrobe Athletic Association” is the first team to buckle one complete season with a formation made up exclusively of professional players (1897).
The first supplemented master key date of the October 27th 1906. Before this date, the master keys ahead were not authorized.
The National Football League (NFL) is set up in 1920 in order to put a term at the underhand dealings which reign then in the world of American football.
American football remains a long time confined in the only United States where it becomes the sport number one, in front of the Baseball, as of the Années 1970. Notable exception, the Japan, influence American obliges, where a university championship since 1947 disputes. The play is introduced in Europe between the end of the Années 1970 and the beginning of the Années 1980. A International federation of American football is created in 1998.
Play
The rules such as they are presented here correspond to those of the American professional championship (NFL). They differ sometimes appreciably according to the competitions. In Europe, American football is practiced thus while being inspired rather by the rules in force in the American university championship of NCAA.
Ground and equipment
The ground
The ground measures 100 Yard S length, that is to say 91,44 m, divided into portions 10 yards. With the center of the ground of the hatched features ( hashmarks ) all the yards for the same reason are laid out longitudinally. These hashmarks delimits the maximum width authorized for the settings concerned in order to prevent that these last proceed too much close to the touchlines. At each end one finds the zone of in-goal called endzone and, at the bottom of this one, the posts between which the balloon must pass for the boot of transformation (after a touchdown) or the boot of placement ( field goal ).
Equipment
The multiplication of the accidents often mortals at the end of XIXe and the beginning of the XXe century, pushed the authorities to make protections obligatory on the level amateur. Each player carries a helmet, épaulières, one protects teeth and from protections on the thighs, the hips, the coccyx, like on the knees. These protections are optional at the professionals. Certain players wear gloves specific to their station. For example, a player of line (“lineman”) will have gloves reinforced with the articulations and on the top of the hand, and a Wide receiver (distant receiver) will have finer gloves with a better adherence for better collecting the ball. One needs also good shoes of American football (shoes for cramps; moulded or screwed cramps). The grids of the helmets are different according to the occupied stations. It is more open for the Quarterback S and receivers who need to have a good vision of the play; they are tighter for the players of line.
The balloon is of form oval and includes/understands a lace allowing the best taken in hand by the quarterback.
Course of the play
Duration
The part lasts 60 minutes effective - but several hours on the whole - and comprises four 15 minutes quarter-times. Between the two first (and the two last ones) quarter-time, one just carries out a change of with dimensions and one keeps the same relative position for the balloon. On the other hand, between 2nd and the 3rd quarter-time, it is the half-time with rest. At the beginning of the 3rd quarter-time the team which received engagement engages in her turn. In the event of equality, a prolongation is exploited the mode of “sudden death”.
Phases of play
An American football game proceeds in two quite distinct phases of play: the attack and defense. The change between the two phases takes place on several occasions detailed low.
The play starts with a boot of engagement or kickoff . This kick is used starts each beginning of period of it (half-time) or to take again the play after a team marked points. It is, in the majority of the case, used to further send the balloon possible in the opposing side. A player of the opposing team must catch up with the balloon and try to advance balloon in hand. The place where the player going up the balloon will be plated will determine the place where the phase of attack will begin for its team.
The team having the balloon is in phase of attack and has four attempts to traverse 10 rods (yards). Once the progression of 10 rods carried out, the team has four new attempts to progress again of 10 additional yards and so on. This is why it is said sometimes that American football is a play of " gain-terrain". If, at the conclusion of the four attempts, the team did not traverse this distance, the possession of the balloon is given to the adversary. The adversary recovers the balloon at the place then where the attack stopped: it is a turnover one downs . To avoid that the opposing team does not recover the balloon too much close to the zone of in-goal and is thus in a situation to mark too favorable, it is possible to type a kick (generally carried out at the time of the fourth attempt) in order to release the balloon. This kick of release is called boot of release. ( punt ).
In phase of attack two means of progression can be used:
the race: In this mode of play the balloon passed directly in person by theback one (Quarterback) to another player called half to the attack ( Running back ). This one must then run with the balloon by avoiding the unfavourable defenders. There exist many alternatives of this type of attack, theback one can for example run with the balloon without making of master key or can transmit it to the running back by the means of a short master key. (It is important to mention that theback one (Quarterback) does not have any more the right to launch the balloon towards the unfavourable zone of in-goal, (passes ahead) at once that it crosses the line of fray ( line off scrimmage ).)
the master key ahead: The quarter-back lance a master key with one of its receivers who will be, au préalable, moved on the ground while following a well defined trajectory. This trajectory, known in advance of the two players, allows, in addition to synchronization between frontier runner and receiver, to destabilize defense by using atypical trajectories. Once the balloon caught by the receiver, this one can continue to run balloon in hand. So that a master key is valid the balloon must be caught without it touching the ground by a player having his two feet inside the limits of the ground. If it is not the case the master key is known as incomplete .
In both cases the whole of the team can carry out blocks in order to protect the players carrying the balloon (quarter-back, runner or receiver). The blocks must be only carried out by pushing the adversary without plating it or holding it.
In phase of defense several methods can be employed to stop the progression of the balloon:
the plating: The goal of the plating is to put on the ground the carrier of the balloon. The play stops as soon as the carrier of the balloon is on the ground, the next attempt at attack will begin at the place where the player was plated. Only a player carrying the balloon can be plated. A plating carried out on theback one is called Sack (If the plating takes place in the zone of in-goal, that brings back 2 points to the defensive team, the safety ). If the plated player loses the balloon, the balloon can be recovered by one of the two teams. This particular event, being able to give place to an inversion ( turnover ) if defense recovers the balloon, is called fumble . (If a player is plated inside the ground, the stop watch continues. If it leaves or is thorough touches some, the stop watch stops. That with a very important impact on the strategy of the play, in attack.)
the interception: It takes place when a defender intercepts a master key intended for a receiver. The defender having carried out the interception can progress balloon in hand until it is plated. Its team will then begin her phase from attack at the place where the plating took place.
To mark points
There exist several manners of marking points:
the test, touched or Touchdown is worth 6 points. It takes place when a player is in possession of the balloon inside the zone of in-goal of the opposing team. It is enough that the ball passes the line of the zone of in-goal so that the touchdown is valid on a play of race or that a player receives the ball in the zone with 1 or 2 feet on the ground according to the championship.
a touchdown gives place to an attempt at transformation, or a conversion. This attempt, played with 2 or 3 yards (2 in NFL) of the line of in-goal can be carried out in two manners:
By striking a kick the same model as the field goal . This type of transformation, called extra point , is worth 1 point.
By marking the equivalent of a touchdown. This type of transformation, called two-point conversion , is worth 2 points. This type of transformation is much more difficult to mark than a kick and thus is generally used only in particular cases where the team must quickly mark points.
the boot of placement or field goal is worth 3 points. A kick to be validated must pass between the two vertical bars of the goal. If the kick is missed, the possession of the ball is given to the opposing team at the place where the kick was struck.
the touched safety or safety is worth 2 points. One touched of safety occurs in the zone of in-goal of the team being in possession of the balloon. It is granted if the carrier of the balloon is plated in its own zone of in-goal or leaves the limits of this one or if a fault of attack is made in this zone.
Faults and penalties
With American football, the penalties are almost never individual, they sanction the whole of the team by a loss yards (5 yards, 10 yards, etc) and/or attempt. The penalties are announced by flags (yellow handkerchief) that one of the seven referees throws by ground when he sees a fault, the principal referee, the referee (recognizable with its white cap), communicates then by gestures with the players and the public to indicate the nature of the fault and consequently the number lost yards. The most current faults are the early retirements, the illegal contacts (in the back for example. Also called illegal block), the seizure of the grid of the helmet ( facemask ) and obstructs it of master key ( not interference ).
Composition of the team
Although there are only 11 players of each camp on the ground during each phase of play, a team comprises a great number of players. The roster (effective) comprises 53 players. The replacements are not limited as in the majority of the other sports but can be carried out between each phase of play. A football team American account thus several specialized formations adapted to the various phases of play. These formations are made up different players although some can belong to several units.
Defense
The team installation in defense can be divided into three principal curtains:
First curtain: This curtain made up of the players of defensive line. Defensive end > (D-end) or defensive wingers and of Defensive tackle defensive (D-T) or platers. This curtain has for double objective to stop the races and to prevent theback one from passing the balloon.
Second curtain: The role of this curtain of defense, evolving/moving between the long and short lines of defense, is mixed. The players of this line called Linebacker or secondeurs must indeed compensate the first line by stopping the races and the third line while intervening on the master keys.
Third curtain: Defensive backs ( defensive backs ). Their role is to thwart the play of master key of the adversary. The players belonging to this curtain are Cornerback S or halves of corner and safeties or petty thieves, the latter acting as ultimate defenders.
The attack
It is made up:
of a Quarterback (QB, also called quarter-back with the Canada) which is that which directs the offensive and calls the plays. It is the first player with touching with the balloon, after the center. It is connected with a half of opening to Rugby, it must have a good vision of the play, an excellent leadership, as well as calm and a coolness with any test. (Contrary to the popular belief, quarter-back the is not the only player authorized to make a master key ahead. All the players can do it, except the center, as long as they do not cross the line of fray.)
of carriers of balloon (Running back S): rapids and powerful, their goal is to cross the unfavourable defensive curtain. There is half-back (HB) very fast, it is connected with a three-quarter centers with Rugby, and the fullback (FB) more powerful but slower in rule general than the halfback, he is also used like cleaner of defense in front of the halfback.
of the distant wingers (Wide receiver S) (WR) (receiver) very fast, nimble and skilful (like a three-quarter wing of Rugby). Legs of sprinter and hands of basketball player, it must receive the long master keys of quarter-back and traverse a maximum of distance balloon in hand (yards after receiving).
of the brought closer wingers (Tight end S) (TE), large, powerful and fast players (3rd line of Rugby), they are very general-purpose and can moult themselves as a receiver as out of blocker.
of five men of offensive line (Offensive Linemen) (OL), imposing workers of the shade who protect theback one from the defenders who could threaten it, and who open breaches in defense for the carriers of ball. One of them, the center, has as an additional function to transmit the balloon to the back quarter at the beginning each phase of play (it is the snap ). The offensive line is subjugated with particular rules which restrict their placement, their classification, as well as the possibility for them of taking delivery of a front master key. It is extremely rare to see one to carry the ball to between-them. They are capital players for the good performance of an attack, but they are generally ignored of the public. This line is composed of the center, the Offensive tackle S and the Offensive guard S.
Special units
These units come into play at the time of quite specific situations. There exist different formations to carry out the boots of engagement, of release as well as the placements (boots of three points or field goals ). Certain specialized ultra players enter on the ground only for these phases of play. It is in particular of the punter which carry out the boots of release, of the kicker, specialized in the kicks placed (transformations and field goals ) and about the Long snapper which replaces the center in some of these phases of play. A special TEAM defensive is also installation at the time of each one of these situations. They act to prevent the opposing team from marking or to go up the balloon most effectively possible in the case of a boot of engagement or release.
Strategies and tactics
The character extrèmement hâché of the play, the principle of the gain-ground and the replacements unlimited led, with the passing of years, the trainers to develop tactical diagrams of a great sophistication. The development of the video analysis and data processing still accentuated this phenomenon. American football is often compared with a form of set of failures whose parts would be alive, and many subtleties escape the spectator even informed.
Strategic philosophies
To build what they call them system , the trainers are brought to make choices on their offensive, defensive priorities and on the special teams. Is it necessary to privilege the possession of the balloon, or to play with the position on the ground? In attack, will one use the play of front master key to release then from spaces for the race, or on the contrary the play it will be based on plays on the ground with from time to time of the pretenses leading to master keys before ( play-action )? In defense, one can choose a risky system but being able to pay large consisting in sending additional defenders to put the pressure on the Quarterback ( blitz ), or one can decide to let the adversary gain gradually ground without conceding broad portions of them, by counting on the fact that it will end up making an error ( the reed folds but does not break ). Finally choices also are essential as for the special units. When is it necessary to release in 4th attempt, when is necessary it to try the whole for the whole?
Offensive formations
The rule of American football imposes that seven players at least are positioned just behind the line of scrimmage . The others must be in withdrawal of at least a rod (1 yard), positioned in the back-field . It is not without tactical consequences because only the latter as well as the players located at the ends of the line are authorized to take delivery of a front master key. According to the system of offensive play, the trainer will thus position the players in order to optimize the result.
Offensive tactics of play
One coarsely distinguishes three ways of doing advance the balloon on the ground ( play of race ): in power (by using the force of the carriers of ball and the offensive line), in speed (while playing so quickly that the second curtain does not have time to react) or in smoothness (by hiding the balloon, by multiplying the pretenses or by playing the option ). In the same way, there exist several types of master keys before: most traditional is the drop back which sees the QB moving back of some steps while looking in front of him (it reads defense) before stopping and to launch its master key. The men of line then form a pocket to protect it. The QB can also leave directly towards outside ( roll out ), it becomes more threatening for defense since it can decide to pass or to run itself. This tactic of play is particularly effective when it is combined with a pretense of race on the other hand ( bootleg ). The disadvantages for the attack are that the precision of the QB is less since it runs, it is exposed more to defense, and it cannot exploit the entirety of the ground any more because a master key “across the ground” would be hazardous.
Lastly, another category of master key is particularly effective against aggressive defenses, it acts of the screen not . In this type of master key, the QB moves back exaggeratedly while the offensive line lets penetrate the defenders and is placed in front of a receiver or a carrier of ball which will have been dissociated. Right before being made sacker , the QB passes the balloon to the receiver who has a genuine screen ( screen ) of protection to progress.
Coding of the formations
The choice of the tactics is dictated in Quarterback by the coach. Then at the time of the huddle i.e. the gathering of the players before the sequence of play, this one gives code name corresponding to the tactic to carry out. At the time of the calculation, the quarterback can still change the tactics into shouting a new code name ( Audible ). Each code name corresponds to a combination worked with the drive by the players. All the formations are recorded in a playbook .
Defensive formations
The placement in defense is free. The defensive formations most current in NFL are the 43 (4 men of line, 3 linebackers and 4 backs) and the 34 (3 men of line, 4 linebackers and 4 backs). Because of great number of master keys before tried in this championship, one frequently replaces players of the first and second curtain by one ( nickel ) even two ( dime ) back defensive additional.
Defensive tactics of play
Among the tactical choices that the trainer of defense must make, there is that of the mode of cover of master key: zone or individual. The defense of zone is less likely to concede broad portions of ground of only one blow. It gives greater chances to the defensive backs to intercept the balloon, but it requires intelligent and disciplined defenders. Individual defense requires more athletic players, it generates less incomplete interceptions but more master keys. It offers also more possibilities as for sending defenders blitzer . Several play are possible in defense like the flex , the standard , the not defense , etc
Management of the stop watch
The stop watch stops when a master key is incomplete , that the carrier of the balloon leaves the ground, after an idle period, a fault, etc and it continues when a player is plated. This adds a dimension enthralling to football: a team which leads to the score and which with the ball in its possession may find it beneficial to play the watch, and to use 45 the second available ones before each setting concerned to make waste time. Under these conditions, the match can thus be finished 2 minutes before the official end if the adversary does not have any more idle periods: theback one (Quarterback) will be satisfied to put a knee on the ground (even consequence that a plating thus not of stopping of the stop watch) and this for its four attempts . In the same way, a team in possession of the balloon, led to the score at the end of the match, will multiply the master keys, and its carriers of ball will make very to leave in key in order to stop the stop watch. A quarterback will be able to even throw the ball on the ground voluntarily, sacrificing an attempt.
Physical qualities
American football is a sport diversified enough in terms of gauges. This sport privileges the powerful gauges and very rapids but one needs also imposing gauges to form the lines or average or smaller gauges for the running back and wide receiver. The Quarterback requires an agility and a vision of the play above all but it must be also solid to avoid the wounds.
In NFL the players are authentic athletes: the majority of the receivers are large sprinters of which some of them come very close to 10 seconds with the 100 meters. They are able to traverse 60 yards of grounds in a few seconds (with the equipment) to turn the head and to collect balls launched out of missiles then to survive the plating of the defenders. It is one of the most impressive sports at the athletic level with players who spend twice more time in room of musculation than on the ground.
It should however be specified that this sport, such as it is applied to the the United States at the professional level, often is quoted like one the most touched of by doping; thus it is explained that the life expectancy of a professional player of American football did not exceed 55 years in the Années 1990.