In American football, most of the violence is contained to a specific part of the field. If a running back gets the ball, he'll advance only about four yards before being tackled. True, long passing plays do go far down the field, but only a handful of people do the sprinting.

Special teams are different. Everybody runs on a kickoff or a punt, often 70 yards downfield. All the while people hit each other from the front, side and behind. They are following a play, but only to an extent. It's one of the few areas of professional sports still as anarchical as youth soccer.

These plays are also quite important. On October 5, 2003, the Kansas City Chiefs beat the Denver Broncos thanks to a punt return for a touchdown in the fourth quarter. A good return team will earn an average of 10-20 more yards for its team than a bad return team. Given that a team will usually punt and kick off between five and 10 times a game, that's a huge difference.

Nevertheless, special teams players do not get the same recognition that others receive. Most fans cannot name any special teams players other than kickers and punters. In my opinion, this is due to the random nature of special teams play — the camera simply does not know who to focus on. A player who can bust the wedge on the kickoff may not make the tackle, but he's done an incredibly important (and dangerous) job.

No one enters the National Football League as a special teams player. Coaches just look for the rookies who seem crazy.

"You've got to be a little whacko. You've got to be a little goofy. There's times I can remember hearing voices and not seeing well; splitting helmets down the middle; sticking your head in and knocking your tooth out; split your lip in two. That's what it is."
—former NFL player and current coach Scott O'Brien

Punts

                   B    G
                   B

                   DL      SL
                   DL   OT
                   DL   OG     PD
PR                    * C            P
                   DL   OG
                   DL   OG
                   DL      SL

                   B
                   B    G

PR = punt returner | B = blocker | DL = defensive lineman
G = gunner | SL = slot | OT = offensive tackle | OG = offensive guard
PD = personnel director | P = punter

The setup above is for when the returning team wants to set up a long punt return. If the returning team wanted to try to block the punt, they would move one "B" on each side to the "DL" positions.

In the punt-return scheme, the center starts the play by snapping the ball. Hopefully he won't miss the punter; it's about 10-15 yards and he's throwing the ball between his legs. The center and the personnel director, seeing they have no one to block, will release down the field and run as fast as they can. (For this reason, special teams centers are often lighter and faster than other linemen.)

Meanwhile, the gunners are in trouble. They each have two blockcers smacking them, and they have to run all the way down field and attack the punt returner.

The punter kicks the ball. Normally, it will have a hang time of 4 seconds. In that time, the punt-team players will run downfield, and the return-team players will be hitting them as often as they can. This is why return teams are often penalized for blocking in the back — there's so much random contact out there, it's hard not to do it.

The returner then either catches the ball or lets it bounce if he thinks it will go into the end zone for a touchback. If he catches it, he can either call for a fair catch or try to return it. If it's the latter, he's hoping that his blockers have done a number on the gunners; otherwise he might get decapitated. If his head is intact, he'll run as fast as he can toward the opposite end zone.

See why these people have to be crazy?

Kickoffs

                                    5
                    F              4 
                                   3 
         W          F             2
                    F             1
KR       W          F        * K 
                                  1
         W          F             2  
                                   3
                    F              4
                                    5

KR = kick returner | W = wedge | F = Front
K = kicker | 1-5 = kicker's teammates

The play begins when the kicker kicks the ball. None of his teammates can be in front of the ball when it's kicked, but since his teammates start from behind him, they can get off to a running start. They'll need to get past the Front players, however.

Like the punt returner, the kick returner can let the ball go out of the end zone for a touchback. However, there are two big differences between kickoffs and punts: First, the returner must not let the kicking team recover the ball, because otherwise they gain possession. Second, if the kicker kicks the ball out of bounds on a kickoff, then the ball is automatically placed 30 yards downfield from the kickoff point. In the NFL, the ball will be placed at the 40-yard line in the NFL, which is a very good spot for the returning team.

If the returner catches the ball and plans to run forward, the Wedge players join hands about 10 yards in front of him and act like his convoy.

The first kicking-team players downfield will be the 5's. It's their job to bust the wedge and not let the returner get on the outside — that is, between them and the sideline. Eventually, their teammates will catch up and there will usually be a gang-tackle around the 25-yard line.

An onside kick is a whole new ball of wax. Remember how the kicking team can gain possession of the ball if the returner doesn't catch it? Well, in an onside kick, the kicking team attempts to kick the ball in a way that the returners won't be able to catch it. Specifically, the kicker will kick the ball low and short, so it dribbles chaotically. It must go 10 yards downfield, or else the kicking team is not allowed to touch it.

If an onside kick is expected, the returning team will send all their players up to the Front area. Moreover, the returning team will choose players who are receivers by trade — that is, good at catching. As the ball bounces around (footballs are an egg-shaped prolate spheroid), players from both teams will whack around each other. It's great fun to watch.

Field Goals

                  DE     W
               LB DE   TE
                  DL   OT
                  DL   OG      
             S    DL * C      H
                  DL   OG       K
                  DL   OT    
               LB DE   TE
                  DE     W

S = safety | LB = linebacker | DE = defensive end | DL = defensive lineman
K = kicker | H = holder | W = wing | TE = tight end
OT = offensive tackle | OG = offensive guard

Unlike the punts and kickoffs, this play rarely extends over the whole field. Instead, it's the mother of all pit brawls.

The center snaps the ball to the holder, who (hopefull) positions it for the kicker, who attemps to kick the ball through the uprights. However, once the defense sees that no fake is being attempted, all of them will try to block the kick.

The main problem for the kicking team is that the tight ends have to block two players. They do this by first taking the inside player and then "rocking" back to get the other guy with their butt. It doesn't always work, and most blocked field goals are due to a breakdown in this area. The wings also have a tough job — they must hip check the outside defensive end while staying close to his tight end, who is depending on the wingman to be the anvil for his butt-block.

(Boy, this sounds pretty gay!)

The defense must also make sure that they do not hit the kicker (unless they block it). Running into the kicker is a five-yard penalty, and the more severe Roughing the kicker is worth 15 yards and an automatic first down. If you block the kick, however, you can maul that kicker all you want.

Sources:
Scott O'Brien quote: http://www.charlotte.com/mld/charlotte/sports/football/nfl/carolina_panthers/6822825.htm
Punt scheme: http://espn.go.com/ncf/columns/davie/1453702.html
Kickoff scheme: http://www.geocities.com/thekickinggame/FGandPATPressure.htm
Field goal scheme: http://espn.go.com/ncf/columns/davie/1457486.html
Thanks to Davidian for cleanup and onside kick help.