Everyone needs to be a good defender in Korfball, as putting the pressure on and intercepting the ball at crucial points, can really be the difference between winning and losing. Players can't run with the ball and can only pivot. Korfball is also a controlled contact sport. This means that during play contact between players of both teams is allowed but that the referee has to react when the controlled contact between players leads to one player gaining an advantage. For instance players cannot knock a ball out of a players hands. The thing that makes Korfball unique though is it's defending rule!
The most important thing you need to know about defending is the defending rule. In Korfball, if a player satisfies the below rule and are classed as defended, then they cannot shoot. Note that players can only defend other players of the same sex. The rule is composed of 4 parts that must all be satisfied;
The feed position (described here) is an assist position that helps attackers, amongst other things, achieve a running in shot. A common technique when this position is achieved is to "cut" the feed. This basically means moving in front of the feeding player, so they are now the closest to the post, to intercept any passes to them from the attacking players. Timed well and you can intercept the pass and win the ball for your team. However if timed poorly, the feeding player could turn with a free shot to the korf. It is worth mentioning for this same reason, that this should only be attempted if the feeding player is not currently holding the ball. Typically it is done just after the feeding player passes the ball out to someone who is likely to attempt a running in shot. By coming in front of the player you are also essentially gifting them a collect position, so only do this if it is preferential to the situation; if the attacking player is likely to attempt a longshot then you have gifted them a free collect for the shot.