A brief summary of what match defence is and one of the ways that it can be played. Match defence is the generic name of playing 1-1 defence but there are many variations possibile on what is outlined here.

Definitions:

Match Defence - As a team each player will be mark (defend against) one player from the opposing team

Forcing - When a defender is marking the player with the disc, they will try to direct the thrower to throw on one side of the field.

Open-side - The side of the field that the team is allowing passes to occur down.

Break-side - The side of the field that the team are not allowing passes to occur on. 

What is match marking?

Match defence is the most popular defensive strategy of defending in Ulimate. It relies on each member of the team playing defence on one member of the opposing team. At the beginning of each point, each defensive player chooses an offensive player to mark - usually selected by standing opposite them on the line. For the duration of the point you will be responsible for defending the player you selected at the beginning of the point. When the player you are defending has the disc you should force apply a force. When they do not have the disc it is your job to attempt to prevent them from getting the disc.

What is forcing?

Forcing is used as part of the match defence strategy to try to give a small advantage to the rest of the defenders. The job of the force is to prevent the thrower from being able to throw to a certain side of the field. In doing this team is able to defend a lot more effectively as all of the other defenders have less space they have to worry about defending. When the person you are defending has the disc, you should position yourself in a way to reduce the range of throws available to the thrower, or to "force" them to take the options you want. Usually this will mean standing on one side of them to make them take the throws on the other side of their body. This is how the open-side and break-side is created.

How do you know which way to force?

Before you start each point someone on the line will call the direction of the force. They will indicate which side of the pitch they want the throws to go to, generally this will remain the same for all players and for the full duration of the point. Some higher level tactics may involve changes to force at different times.

There's lots of terminology around the direction of the force, some of which are explained here:

Backhand/Forehand - This version of the call refers to the side of the field that we are allowing the opposing team to throw on, this is always given from the perspective of a right handed player. A force of backhand means that a right handed player should be allowed to throw on their backhand side but should be restircted when trying to throw a forehard or onto this side of the field.

Left/Right - A call of left/right designates which side of the field will be the open side, as given from make all players throw toward the left/right sideline as seen from your defending end zone looking down the pitch

Home/Away - Sides of the field can be labelled as "home" or "away" usually the "home" sideline is labelled as the side of the pitch that is closest to the players belongings, i.e. where you've put your bags.

Other calls - Sometimes sides of the field may be labelled as other things such as reference to a landmark in the direction of one of the sidelines or in reference to being upwind or uphill.

How do we mark players without the disc?

When the player you are defending does not have the disc you should position yourself on the open-side. Because the force is only allowing throws onto the open-side, the other defenders have a small advantage as they know that the cutters can only recieve the disc on one side of the field. When you are marking a downfield player, you should try to be on the open side of the player, i.e. between them and the sideline that the force wants them to throw towards. Where possible be between them and the disc too.