Why is the Man-to-Man defense used so rarely?

The principal reason a man-to-man defense can be effective in basketball, but is extremely risky in Handball, is directly related to the locations of high percentage shots in both sports. In basketball there is only one spot for a very high percentage shot: immediately near the basket (i.e. a layup). In Handball, the entire 6 meter line with the exception of the extreme wings is the equivalent of a basketball layup. In basketball, a defender who is beaten can usually count on help from another defender to immediately step in between the offensive player and the basket. In handball, a defender can step in to help, but there is usually too much area on the 6 meter line for him to stop the breakthrough player.  more