I spent Wednesday afternoon re-watching and taking notes on the championship game clash between San Francisco 49ers and New York Giants from last season to prepare for this post. The game was quite good and the 49ers defense exhibited strong technique in coverage while the Giants threw the ball short and Eli Manning threw his receivers open even when they were covered like glue. I’m not entirely sure what this means going into Sunday’s game between the two teams, but I’d like to think we’re going to see more of the same.

The Giants will have to create yards after the catch and contact because they are going to be throwing short a lot once again, with a slight chance of a deep ball if they get the right look. Meanwhile, the 49ers will likely be playing more of their press-man (used to reroute), two-deep coverage variations, especially if Hakeem Nicks returns. The spent a lot of time in that alignment during last January’s playoff meeting because of their overwhelmingly kick-ass defensive line.

San Francisco’s two-deep coverages were used to put a cap on the Giants’ vertical passing game, most of which consists of Victor Cruz running from defenders. ¬†They played five main coverages in the game as I recall: Cover 1/Man-Free, Cover 1-Robber, Cover 2-Man, Cover 3 and Cover 4. And they were all presented out of a 2-high safety shell, with the goal to make everything look similar until the snap, and make Manning uncertain about his keys and reads.

Cover 1 — also known as Man-Free — can be simply described as one deep, free safety playing in zone coverage and the rest of the defenders, including the strong safety, in man coverage. Cover 1-Robber is slightly different. There is still one deep safety — in this case, after the snap — but the other safety is in a “Robber” role underneath, looking to jump crossing routes in an attempt to force a turnover.

1-Robber.

Cover 2-Man or “Man-Under” as some call it, has gained in popularity around the NFL because it enables the defense to create “bracket” (double) coverage on receivers with defenders underneath and above the route. This was another coverage that the 49ers showed a two-deep shell on again, but actually stayed in it post-snap. It features two-deep safeties and man coverage underneath.

Cover 2-Man/Man-Under

While Cover 2-Man sees the 49ers stay in a deep shell, Cover 3 does not. Cover 3 is a 4-under, 3-deep zone coverage that has one safety roll down into the middle of the field as a “Hook” defender, accompanying another inside defender and two “Curl-Flat” (C/F) defenders on the edges of the field. Deep, there can be various combinations, but as shown in the image, the 49ers played with two deep cornerbacks and one free safety patrolling the middle as the three split the field into thirds. This choice of coverage was significant in stopping the run, as it allows the strong safety to quickly read his keys as he comes down into the tackle-box.

Cover 3.

Last but not least, Cover 4 was used, and there are multiple variations of it. It should be noted that the 49ers used several forms of this, including what some will call “2-Read,” pattern matching (akin to basketball’s zone defense), traditional Quarters coverage, four deep defenders splitting field into fourths similar to prevent coverage, and what’s pictured below: the cornerbacks manned up against the No. 1 receivers while the two-deep safeties eyeballed the No.2 receiver from the formation. If the No.2 receiver ran an underneath route or didn’t run a certain distance — eight yards, for example — then the safety would form bracket coverage on the No. 1 receiver.

Cover 4 or Quarters coverage.

What this all means for the Giants offense is that they are going to have take their deep shots in certain situations where they feel they are getting the right look — which is difficult because it all looks the same — or bank on the chance that the 49ers defenders get out of position.

If there are a couple of players who will give the Giants an opportunity with the deep shot, it could be one of the safeties.

Dashon Goldson possesses the foot speed to cover ground and is a willing player in run support, but he does have an issue with taking the right angles in coverage. He tends to take too narrow of an angle while attacking the ball, and as a result opportunities for yards after catch or potential deep shots open up. There is a possible chance the Giants attempt a double move in his direction to make him bite hard and then throw over the top.

Donte Whitner can also be overly aggressive at times as witnessed at the start of the second quarterback in the playoff game.

With the ball on the left hash, Nicks and Cruz were on the wide side of the field, and offensive coordinator Kevin Gilbride was able to call his favorite “Switch” concept that has option routes built-in but often sees the Giants run a Dig-Wheel combination against defenses. This worked because of the safety rotation, with the strong safety (top of the screen) rotating down to account for Nicks’ Dig route, and consequently leaving Cruz in a one-on-one matchup down the sideline with the cornerback that resulted in a 36-yard reception.

Switch

Finally, the potential return of Nicks is significant because it will affect the way the 49ers play coverage. Nicks is a threat on the outside and in the middle of the field, where he often runs Dig routes. This was a big reason why the 49ers played their two-deep coverage shells, and if he’s absent, there is perhaps a chance they play less of them and get even more physical downhill with the Giants receivers.