In both sets, the nose tackle lines up over center or in the center/guard gap. In a 4-3, the nose tackle usually gets called a DT to simplify things but he's still a nose tackle in effect playing 0 technique with the other DT usually being a player playing 3 technique, lining up wider (between the guard and tackle) looking to shoot the gap and along the nose tackle to draw the natural double team and tie up blockers. Some 4-3's will play both DT's 3 technique or 1/2 technique but the 0 and 3 technique is the most popular.
One of the reasons the 3-4 is effective against the run is dependent on the d-line. They are now expected to tie up the blockers so that the more athletic linebackers are freed up to attack the running game. In the past days (my youth 70's & 80's) the defensive linemen were the attackers....fearsome foursome,purple people eaters and steel curtain to name a few but now the linemen are meant to plug up lanes and not so much to do the tackling.
Free is sometimes called the weak safety too. Basically, the weak/free safety defends the side of the field without the tight end, playing deeper and more centeral, the strong safety plays on the side of the tight end and closer to the LOS although lots of defensives interchange and in the cover 2, both safeties tend to play deep(er) although which side they line up on will refer to how their positions are called.
In todays defenses also...unlike older ones. there isn't that much difference between the 3-4 and 4-3 because usually one of the defensive ends is nothing more than a linebacker lined up as an end to rush the pass and the nose tackle is just offset like Mean Joe Green used to line up just off to side of center. It is funny how great defenses of yester year affected what are now called schemes of today. Remember when defensive lineman were all big brutes that used the bull rush? Then a player like Allen Paige comes along who is smaller and quicker and athletic and can get to the qb and things start to change then the coaches get smart and develop defenses just for that type of player....they've come a long way.
He didn't get the 2 point conversion, but the refs said he did...so ...we got screwed, but it's only preseason...I'll save my yelling for the Real games!
A typical 3-4 defense uses three strong, smart linemen that are more geared towards strength and taking up blocks, giving the speedy outside line backers an easier route to the quarterback. The MLB's will be bigger, stockier players capable of shedding blocks and attacking the line of scrimmage. CB's will be physical and able to help in run support. Safety's have to be versatile, because 3-4 blitzes can be very complicated and there needs to be a last line of defense..
So who here can explain a zone blitz package? What style of players do you need and why is it effective and what type of team is it not effective against?
The zone blitz came about as a way to blitz but not to have the risk of man coverage behind it that can lead to the big play. The basic idea is to confuse an offense, not allow them to guess where the rush is coming from and exchange zone responsibilities between players to cover for the zone that is losing it's responsibility in the blitz. For example, a team might blitz a MLB, the OLB might swing over to take his coverage responsibility and then the DE will drop into coverage where the OLB shoudl have been. Some zone blitzs are very simple, ie, the OLB will come and the DE he lines up behind or near, drops into his coverage zone. The beauty of it is offensive linemen will not be sure who to pick up as well as running backs or tight ends who may have some pass pro responsibilities. Also, normally when a blitz comes, the QB has a hot read, but as the zone blitz is moving people about in coverage responsibilities it can be hard for the QB to even see his hot read or be aware to go to it until it's too late. The disadvantage is that it asks players to move about to get into a zone and if they mess their coverage up, it leaves a gaping hole. Also, when using defensive linemen in coverage, it's not a responsibility they are used to.
A zone blitz quite simply is when a player that is not expected to rush the passer (such as, say, a safety) is assigned to rush the passer while a player who is expected to rush the passer (such as a DE) drops back into a short or medium zone coverage. The design is to confuse the offensive lineman to the point where they don't pick up their assignments correctly, thus freeing a pass rusher to a clear path to the QB. The only type of player that is required for a zone blitz to be effective is athletic DLmen that are capable of playing zone coverage. An example of this, using the Steelers, who tend to be the most effective zone blitzers in the league, is as follows: The Steelers line up in their normal 3-4 alignment (players will be in alignment as shown here). On the play, Aaron Smith will drop back into a short-intermediate zone coverage on the right side of the field, Ryan Clark will drop into a deep zone coverage in the middle of the field, James Farrior will drop into a short-intermediate zone coverage in the middle of the field, James Harrison will drop into an intermediate zone on the left side of the field, and Bryant McFadden and Ike Taylor will be charged with deep sidline responsibilities (a basic Cover 3 zone). Meanwhile at the line, Casey Hampton is charged with his usual 2 gap responsibility (taking on both the C and RG), Larry Foote is blitzing in the middle (should be picked up by the LG), Brett Keisel is charged with his usual 1 gap responsibility (he will be facing off against the LT), and Clark Haggans will be blitzing from the outside (he should be facing off against the RT). The extra blitzer on this play is Troy Polamalu. As the opposing offense lines up and gets ready to snap the ball, Polamalu will creep up near the line of scrimmage, toward the middle of the field. If all goes according to plan, at the snap of the ball, Hampton will push the center and guard to the right, Foote will push the LG to the left, creating an open lane for Troy Polamalu to get to the QB with no chance of either of the tackles sliding over and helping, because they're busy blocking Keisel and Haggans. If this happens, it should result in A) a Polamalu sack or B) a bad throw by the opposing QB which could possibly be intercepted. If all does not go according to plan, however (namely, if Hampton and/or Foote fail their assignments), Polamalu will not have a lane to go through, and if none of the other blitzers beats their man, the Steelers will be in a Cover 3 zone, and, just like any other zone coverage, it has holes that the opposing QB can exploit, but it will have bigger holes because the Steelers have sent 5 instead of the normal 4, and they have a DE playing in coverage.
what are the yard penalties on defense? The diference between offsides, encrouchment, etc.? What is the halo rule and does it exist in pro football?
Offsides is given if the defensive player is passed the line of scrimmage when the ball is snapped, encroachment occurs when a defensive player jumps offsides and makes contact with an offensive player before the snap. They can avoid being offsides if they can manage to get back onside before the ball is snapped without touching an offensive player. The halo rule is used on punts to protect the receiver from getting hit as he catches the ball. It is not used in the pros, however a receiver can call for a fair catch and avoid the hit.
I believe the halo rule is used in the pros, it's just not called the halo rule anymore. There needs to be a "space" granted to a kick/punt returner from the rule book if I recall correctly.
Offsides and encrouchment both carry 5 yards and a repeat of the down (unless the yardage makes it a first down). The only time it differs is inside the 5 where the penalty is half the distance to the goal line. Other defensive pens off the top of my head. Pass interference, spot foul, automatic first down (at the one if occurring in the end zone). Defensive holding, 5 yards and an automatic first down. Good link here: http://www.nfl.com/rulebook
