In football How do you get half of a sack?

When two players reach the quarterback at the same time and make the tackle, the sack is divided between the two players. Same with tackles ... you might see in the game's statistics where a defensive player had 5.5 tackles. This is because, when two players are responsible for bringing the ball carrier down, regardless of whether it is the quarterback or another offensive player, the sack/tackle is divided between the two defensive players.