As FIFA (fancy French acronym for the world's soccer federation) likes to say, it's as easy as 1-2-3:
2. Involved in Active Play
3. Offense (they use offence, we don't)
There is a lot of parent and coach confusion on the offside rule, and it's the rare spectator who has a better perspective on it than the Assistant Referee, which is why the AR should almost always be lined up with the second-to-last defender or the ball (whichever is closest to the goal line.) By lining up this way, the AR is then probably the only person who knows whether the player is in the offside position and is involved in active play at the moment the ball touches or is played by one of his team.
Here are a couple of great resources to review the offside rule:
The restart for an offside offense is an indirect free kick (IFK) from the position where the infringement took place, which is where the offside player was at the moment his teammate passed or touched the ball, not necessarily at the location where you judge the offside player to have been involved in the play. Tricky? Yes. This is why we get paid the big bucks. As an AR, you're lined up with the next-to-last defender (right?!), so you're marking the "moment" the attacker is in the offside position. Some refs stay in that position and follow play to determine involvement in play (that's usually pretty quickly), then signal offside. With that you've marked the spot, and sticking with it. The problem with that is that is if the offside doesn't materialize, then where are you should something else happen like, maybe, another offside? Probably better is to remember roughly where you were at the moment and move downfield to stay lined up, if the offside then materializes, raise your flag, get the signal from the CR, go back to the position where the "moment" occurred and signal the position (near, mid or far side of field) for the restart (see #3 here). The IFK should be taken from where you've lined up.
Diagonal System of Control
The Diagonal System of Control is the only system of positioning used by referees in AYSO for U9 and above games. The system consists of a referee (sometimes called the center referee (CR)) and two assistant referees (ARs). By use of this system, and by having play be "boxed" between the CR and the AR, the referee may officiate in a fluid motion without needing to turn his back to the play, stop, and then turn around sharply. More detailed information may be found here.
Referees are encouraged to step off the field of play (the pitch) as needed to keep play boxed between themselves and the ARs. This way there are two sets of eyes on play at all times.
Mentoring is an excellent way to gain tips, tricks and advice from more advanced referees. Most of the advanced referees in the region have been mentored at one or more times in their career. Mentoring is typically done in one of the following ways:
For more information, please contact our Regional Referee Mentor at email@example.com.
It's actually easier to maintain control and authority if you are calm and project that calmness. However there are many opportunities where a referee can be challenged:
Here's some advice:
Game (Lineup) Cards
Game cards are required for every U10+ game.
Game cards should be held by the AR who monitors substitutions, and turned into the CR at the completion of the game.
CR should hold onto the cards until the end of the season, and should enter the game card information into the Region's system as per the below at the end of every game.
This is ESPECIALLY CRITICAL AT U12 AND ABOVE, where game cards are used for standings.
Game cards should be filled out and entered per the Game Card page.
A great collection of resources is the United States Soccer Federation (USSF) Resource Center. Check it out. Some of the resources located there include: