The footy field is so big that the way it is typically filmed, it's very difficult to get the gist of the rules or even how the field is set up. The camera gernally just follows the ball so you don't get the big picture. I didn't understand all the rules until I joined a club and started playing. For a good overview of the rules and the sport, go to
www.usfooty.com and click on the link labeld "The Game".
Basically, a
Behind is when the ball is kicked through the outer poles.
If I kick the ball at least 10 meters and you catch it without anyone else touching it, you are awarded a
Mark. That means you get to kick the ball unopposed. This is when you see the guy back up with the ball and the defenders leave him alone. If you get a Mark, you can also decide to Play On by running with the ball or hand balling it away (basically punching it out of your hand).
You can run as long as you like with the ball, but you must bounce it or touch it to the ground once every 15 meters. This distance is totally subjective and up to the officials. For those at home, running at full speed attempting to get an oblong ball to bounce and return to your hand is no easy feat. So sometimes you'll actually see a guy touch the ball to the ground.
You can pretty much tackle anybody carrying the ball as long as you don't hit them in the neck or higher.
Shepherding is when you physically prevent an opponent from getting to the ball. Think
Blocking or setting a really hard pick. But you can only do it within 5 meters of where the ball is.
This is such a fun sport to play. I wish it would get more popular here in the states. For those interested,
www.usfooty.com is the home site for our own league in the US. Most of the clubs are always looking for new recruits or fans.