For the fourth time in as many years, Wembley stadium will host an NFL regular season game at the end of the month.

This time the two teams are the Denver Broncos and San Francisco 49ers, the latter being one of the most globally recognised American football teams due to their success in the 1980s.

Since the first NFL game at Wembley four years ago, there has been a significant rise in the amount of teams in England as well as participation numbers.

Andy Fuller, BAFA (British American Football Association) director for student football development, attributes the increase in teams and participation to two important factors.

He said: “Firstly, the universities (and teams) have invested a lot of time and energy into raising the awareness of the sport to students. Secondly, the NFL on T.V. and the Wembley games. We've seen a double digit rise in the amount of people participating over the past four years (since the first Wembley game). The NFL is best recruitment tool we could ask for.”

There are currently eight American football teams in the London area including the London Olympians who are based in Crystal Palace. The Olympians have enjoyed recent success after being crowned Britbowl Division Two champions completing a season where they went undefeated.

The University of Surrey, too, have a team which in the past was made up of Surrey students and Kingston University students in equal measure. New regulation from the BUAFL, however, means that Kingston must set up its own team ahead of the new season.

Susie Finnis, Kingston University students' union sports co-ordinator, said: “We'd love to have an American football team but setting up by ourselves will take a lot of funding. When Kingston students were playing for Surrey, they paid all their membership fees to the University of Surrey.

“If we could have one we would and I will be meeting with Sport England (who teams apply to for funding) this week to see what we can do.”

Fuller adds: “What Kingston need to do is put together a three phase project. Firstly, a feasibility test, whether there is enough demand for the sport. Secondly, they must put together a business plan to show where they will get their funding and then how they will put that business plan into operation.”

BAFA is the national governing body for American football in this country with four member bodies, including the BUAFL (British Universities American Football League). The BUAFL is Europe's largest university competition for the sport, another example of the rising interest in the sport, as fans continue to watch it but now more people are looking to participate. During the BUAFL's first season (07/08), three new teams successfully joined the league. Last season that number rose from three to 20 new teams looking to join the league, prompting a reshuffle of divisions and conferences.

The fact that this year's Wembley game is the fourth instalment of the NFL International Series and that the last three games have all been sell outs is evidence of the sport's ever growing popularity in this country. The first sale of 45,000 tickets for the event in May sold out in 90 minutes. Never destined to be more popular than football or rugby, there is still a very strong following for American football, dating back to the 1980s when Channel 4 began to broadcast a weekly NFL highlight show.

As of September 2010, Channel 4 have started to broadcast a weekly NFL game on Sunday night and Sky have been broadcasting over 125 live NFL games for the past three years. The BBC also have a section of their sports site dedicated to American football as well as broadcasting the last three Super Bowls live.

This year, NFL UK have added a pre-game rally, being held at Trafalgar Square, to the International Series experience. There will be cheerleaders, interviews with 49er legend Jerry Rice and current coach Mike Singletary, as well as live DJs and music.

NFL UK Managing Director, Alistair Kirkwood, said: “It's a historic, can't miss event.

“We expect many newcomers to the NFL to be able to come along and have a great time and we are creating a programme of events and activities to cater for all levels of NFL interest – even those who have very little idea about the sport. There will be something for everyone.”

The NFL Trafalgar Square rally will take place on Saturday, October 30, beginning at 1pm.

The Denver Broncos will play the San Francisco 49ers at Wembley Stadium on Sunday, October 31. Kick off is at 5pm.

American Football – Basics Field Goal = three points Touchdown = six points American football field is 100 yards in length with an extra nine yards on both ends, called the endzone. Moving the ball down the field and into the endzone will result in scoring a touchdown.

A team can move the ball towards the endzone by either running the ball or the ground or the quarterback passing it through the air.

One American football team is made up of three different units: offensive, defensive and special teams and there must be 11 players from each team at any given time.