Stay with your mark and don’t let them catch the disc. Go wherever they go and also try to keep an eye on the person with the disc. If a flying disc comes near you, try to catch it or knock it down. If your check catches the disc, put the force on them. That’s it.

When you are starting out, you can get away with pretty much anything. Drop all the passes you want- nobody’s going to care (too much). But there is one thing you must do: stay with your mark.

Run. If they are running away from you, focus on their back and run. If they faked you out and are going the other way, run after them. If your team turned it over and now your mark is gone, go get them. Don’t give up, that’s all your teammates ask of you.

You could jump around and try to get in their way… but that would just tire you out. They would probably just fake you out and throw around you. Instead, cut your losses and try to force them to throw to only one side of the field. This is called “forcing the thrower”.

Do this by standing slightly in front of and to one side of the thrower. Hold your hands out down low. Sure, this makes it easy for them to throw to the other side- but that’s the plan. Before the point began, everyone on your team agreed to force the throwers to a chosen side of the field. Since everyone on defence knows where the throws will be going, they know where the offence will want to run. If everybody sticks to the plan, defence is much easier.

The force is perhaps one of the most overlooked aspects of defence. So what is the force? In short, it's a designated area of the field that you are letting your opponents throw to. Examine the diagram below and then read on.

First off, your team (on defence) must designate a "home" and "away" side, usually home is where you placed your bags and water.

Next, before you pull to the receiving team, your team will decide if you will force the opponents "home" or "away". In this example, the defense is forcing to the "home" side, so the "open" side is any part of the field to the right of the offensive player.

The crucial aspect of the force is the person marking the player with the disc. In the diagram above, the player is being forced to the "Open" side, this is shown by player 1 who is standing to the left of player 1. Things that are not obvious from this picture are that the defending player should have their arms and hands spread out to cover as much space as possible, therby making it more difficult to throw to the "Break" side (called "breaking" the force).

The next important ingredient to the force are the other defenders marking the rest of the players. Because you know where the player is being "forced" to throw, defenders can place themselves in this area to make it harder for offensive players to cut. In general, all defenders should be positioned in the "Open side" in between their opponent and the disc, the only exception is with the last defender (deepest or closest to the endzone), who should play a bit behind their opponent to cover any long throws.

Here are some of the forces your team could use and their purpose:

• Force Middle: This force requires dividing the field into two equal sides (left and right). When the disc is on the right side you force left, when the disc is on the left side you force right. In the cases where the disc is in the middle, like off a pull, your team should just make a default force to avoid any confusions. Lastly, it's imperative that you call out the direction you are forcing every time you mark up. It's better to force the wrong way and have your teammates know, so always yell out the force. Forcing middle is a good way to confuse the offence, and can be very effective against vertical offence. On the other hand, forcing middle against a horizontal offence is usually not the wisest choice.
  
  
• Force Line (Trap): Forcing in the direction of the line is usually done when the disc is near the sideline, although you can treat it as a reverse force middle and force sideline at all times. Forcing sideline is especially useful when the offence is near the endzone and close to the sideline. Often, teams will neglect the dump and swing approach and will try to throw into the small opening.
  
  
• Force to a Particular Side: This is the most basic idea, as was discussed initially, force one direction so your defence can control the offensive flow.
  
  
• Force Wind: Forcing wind is similar to forcing to one side, except you force the team to make the "harder" throw. That is, if the wind is blowing hard left to right, the defence can make it harder for the offence to throw by forcing them in the direction of the wind (left). The direction you chose to force is really dependant on the type of wind, sometimes throwing into the wind is easier, so it's not a golden rule to force into the wind.
  
  
• Trap For One: Trapping is another word for forcing sideline when the disc is near the sideline. So, Trapping for One implies you force sideline until they get the throw off, and then you switch back to your original force. Trapping for One is often used in zones where you want to push the offence to the weak side (the side where the wind is blowing strongest). In a zone, this equates to giving the handlers the free throw to the weak side, and then switching the force and putting on a trap once the disc is on the sideline of the weak side.
  
  
• Force (Straight) Up: Forcing up, or straight up, means you don't force to the flick or backhand side but stand perpedendicular to the sideline. This should cut off the hucks and force teams to make more modest gains by throwing shorter passes. Since the handler will have both sides to throw to it will be easier for the offensive cutters to get open, so the defence must adjust by "fronting" their checks. In most cases, forcing straight up is done on the first few passes to stop any huck plays, or in situations where the wind is blowing very strong.
  
  

Since ultimate is a non-contact sport, when you are forcing the thrower you have to give them some space. How much space? A flat disc should be able to fit between your bodies. This is known as a “disc space”.

In order to keep the game moving, the thrower is only allowed to hold the disc for ten seconds. However, somebody on defence has to be there to count these ten seconds out loud. If no one is counting, then the thrower can have the disc all day. If your mark has the disc, put the force on them and start counting. Say “Stall one…stall two…stall three…” up to stall ten. There should be a second between each stall. If you get up to ten and they still have the disc then yell “Down” and the disc now belongs to your team.

1) Know where your mark is. If you don’t, they’re probably gone.

2) Stand on your toes. Keep your feet moving. If your mark gets the jump on you, they’re halfway to being open.

3) Know where the force is. This will tell you where your mark is likely to cut.

4) Know where the disc is. This will tell you where the throw will be coming from.

5) Stay between your mark and the disc. Because you don’t want to turn your back on your mark, you’ll have to backpedal or stay right beside them. The thrower will think twice if you’re in the way. (See #6 for the exception.)

6) If your mark is last in the stack, stand behind him. This allows you to get the jump on any huck plays.

7) When outnumbered, mark the person closest to your endzone. If there has been a quick turnover or the other team has hucked it, your defence will often be outnumbered. You have to decide which person to mark.

It doesn’t matter who you were marking before. Ignore the person with the disc- they aren’t going anywhere. Go get the person who is closest to your endzone, they are the greatest threat.