Volleyball Girls

Blocking is also classified according to the number of players involved. Thus, one may speak of single (or solo), double, or triple block.
Successful blocking does not always result in a "roof" and many times does not even touch the ball. While it’s obvious that a block was a success when the attacker is roofed, a block that consistently forces the attacker away from his or her 'power' or preferred attack into a more easily controlled shot by the defense is also a highly successful block.
At the same time, the block position influences the positions where other defenders place themselves while opponent hitters are spiking.