 In the last video, we took a look at some of the most common types of offensive plays. So let's flip things around and take a look at the defensive side of the ball. On most plays, the defensive linemen will be attempting to just get to the quarterback as quickly as possible. So most of what we're about to look at will primarily be concerned with what the linebackers and defensive backs will be doing. Like many other sports, the two general coverages the defense will use in football are the man-to-man and the zone coverage. In man-to-man, each defender would be assigned to a specific offensive player and it is their job to stop that player from catching the ball, or if he does, tackling him as soon as possible after he does catch the ball. For example, the cornerbacks would be assigned to cover the wide receivers while the linebackers would be assigned to the running back or a tight end. You'll notice that because there are five offensive linemen in the quarterback on offense, this will lead to the safeties and the defense of linemen without a pair. Again, the linemen will probably just be rushing and we will come back to the safeties in a second. But of course, the weakness of a man-to-man defense is that good receivers will have an advantage if only one defender is covering them. It will also allow the offense to spread things out so that they can have more room in the middle to run the ball. If we take one step away from the man-to-man, we would get the cover to defense. This would mean that both of the safeties would hang back in order to give support to the corners if the ball is thrown deep up the field. There are many additional variations on zone defense all the way to the other extreme in which all the defenders except the linemen would have an area they are responsible for. You might hear other coverages mentioned like the cover three or the cover four. Each of these different numbers all the way up to the cover six refers to a different type of zone coverage alignment. Obviously the weakness in zone defense is that things can get difficult when there is more than one receiver in your area to cover. This is why there are the different types of zone defenses. One term that you'll probably hear at some point during a game is a blitz. This refers to a type of play in which the defense will send an extra player to try to tackle the quarterback. So let's go back to our free safety in the man-to-man setup again. More times than not he will roam around in the middle of the area of the field. He is essentially free to go anywhere hence the name free safety. So let's say that on this play rather than hanging back in the middle of the field the defensive team calls for the free safety to blitz. Since the defense of players can move around before the snap he might work his way up to the line of scrimmage and then when the ball is snapped he will run in for the quarterback as quickly as possible. This type of blitz would be called a safety blitz. Alternately they might try to fake the offense out by lining up as if the safety is going to blitz but instead he covers the wide receiver while the corner back blitzes. As you might suspect this would be a corner blitz. Most commonly though we will see a linebacker blitz. You may even see a defensive end drop back into coverage while the linebacker goes in for the quarterback. One final defensive term to explain is the box. This refers to the general area that is about as wide as the offensive line and about five yards deep into the defense and most formations the linemen and the linebackers will be said to be in the box so that makes seven guys. When you'll most likely hear the announcer on TV make reference to the box it'll be when they start adding or removing defenders from it. On plays close to a first down line or the goal line you might see a team bring ten guys into the box and then attempt to block up the middle of the field and make it very difficult to run against. The flip side of course is where a team could spread out the receivers then the defense then may reduce the number of players in the box which in turn would make it much easier to run against. So defensive strategy has been evolving for decades so we could spend a great deal of time on it still not get to everything. Luckily as long as you have somewhat of an understanding of the different defensive formations and strategies you will have no trouble enjoying a game. After all it always goes back to the simplest goal. That's the guy with the ball.