Coaching defense in the era of 11 personnel, the rewards of throwing the ball down field, and the proliferation of the fullback has forced defensive coordinators to make nickel defense as big a part of their game plan as their base defense.
For argument’s sake, nickel defense will line up in some sort of 4-2-5 look. The 5 in back are who we should spend some time on, as well as touching on who the 4 and 2 are (as opposed to base defense).
Teams that play “Regular Nickel” are playing with 2 safeties, and 3 corners.
This allows the defense gets its best “cover” guys out on the field while still being able to have 2 high safeties in the back end. Every coverage a defense has in its playbook is in play with this personnel. The issue though is they have forsaken their run defense when they take the Sam linebacker out of the game and replace him with a corner.
Some teams have resorted to pulling the Mike out for a corner, and leaving the Sam in the game to hedge on the run game.
If Down and Distance indicates that a run play is a threat on 2nd & 4 with 11 personnel and a team likes their “regular nickel” against this particular matchup, a team may be tempted to hedge its bets and leave the Sam in and hope they can cover up his warts as a pass defender with their back 5.
There has been a movement with teams to play “Big Nickel”.
Basically, instead of having 3 CB’s and 2 Safeties, teams flip it and have 2 CB’s and 3 Safeties on the field. What this says to an opposing offensive coordinator is “we are gonna play nickel defense against your 11 personnel group, but we will not hand you the running game on a platter”.
The 2 positives of playing big nickel are
1: getting the Sam LB out of the game. He is typically the worst pass defender, so he’s a liability in the pass game, and he can’t carry the TE (Y) on deep over routes unless he’s an All-Pro-caliber Sam LB.
2: This is hedging the bet against the run game by putting a 3rd safety in the game. This is a guy who does not mind becoming a box player if he reads run. He also is a better candidate to blitz than a CB would be.
Teams that play “Big Nickel” will typically play it on normal Down & Distance (where the threat of the run is greater) and on 3rd & Long will look to play “Regular Nickel” or just straight up “Dime” (6 DB’s) defense.
However, there is a bit of a downside to playing “Big Nickel”. Typical 3rd Safeties are not going to be able to cover a regular S (slot) receiver man to man. They can get eaten alive by guys like Cole Beasley on shallow crosses and all the quick game routes these types of receivers will run.
To give the 3rd safety help, teams have to either help him with giving the LB’s some coverage responsibility so the 3rd safety can cheat and get deeper. They can also flip it and give him help by playing the Free Safety behind him, therefore allowing him to sit and squat on the short and intermediate routes.
Either way, a DC is really stressing out the coverage on other players to try to help the 3rd safety. In addition, the combination of coverages you can now play are reduced as opposed to when you’re playing “regular nickel”.
As with everything in defensive football, the game is to always hedge your bets and play the scouting report and film evaluation. There is no perfect defensive scheme, so there are times when teams just have to pick a poison and then make adjustments as each play happens.