"We played more split-safety coverage after the first drive," Patriots coach Bill Belichick said during a press conference on Monday. "I don't think that was all of it, but I think that might have had something to do with it."
For the layman, here's how Belichick described split-safety coverage: "Where there’s a safety over the top of the receivers, which gives the corners an opportunity to play down on them a little bit tighter because they are backed up -- as opposed to having a middle of the field safety on the outside perimeter routes, there isn’t anybody behind him."
Along those same lines, Belichick was asked immediately after the game on Sunday why the Patriots spread the ball out so much and used their running backs so much in the passing game.
"Well, they played a lot of coverage over Randy (Moss), like we expected, with (Ed) Reed over the top, and so they took a lot of those plays away," he said.
Let's go to the chalkboard to figure out a little bit about how the Patriots and Ravens utilized their safeties to take away their opponents' best wide receiver -- and how that played to the Patriots' advantage. (Mason and the Patriots' safeties will be highlighted in yellow.)
Baltimore's first drive
First-and-10, 33-yard line going in
Mason already had three catches to this point in the game, including a catch for 17 yards to kick-start the drive deep in Patriots' territory. The Patriots lined up in a basic 3-4 defense with two cornerbacks and two safeties. Some specifics:
* The Ravens split two wide receivers out to the left, and safety Brandon McGowan and cornerback Leigh Bodden lined up across from them. Bodden lined up across from Mason.
* Jonathan Wilhite, the other corner, lined up opposite tight end Todd Heap on the opposite side.
* Brandon Meriweather lined up as the deep safety.
Mason and Mark Clayton, the other wide receiver, both ran relatively short routes, and with Meriweather still playing center field, Bodden had to give Clayton more than enough cushion to make a catch for 12 yards and a first down:
The result: An easy first down.
Contrast that to the way the Ravens defended the Patriots on a play on which Tom Brady was forced to throw a dump-off pass to Laurence Maroney. This time, Moss and the Ravens' safeties are highlighted in yellow.
New England's second drive
First-and-10, 45-yard line going out
* The Patriots lined up two wide receivers to the right of the formation -- Moss and Wes Welker -- and two tight ends to the left.
* The Ravens lined up in a nickel defensive package with three defensive linemen and three linebackers with three cornerbacks and two safeties available in coverage.
* When Welker went in motion at the snap, it looked like this:
Correctly anticipating a pass, the Ravens dropped into coverage -- and by splitting their safeties, Reed was able to focus mostly on Moss going deep while Dawan Landry, the other safety, mostly played center field on the other side.
Brady, despite all the time in the world given to him by a lackluster pass rush, could find no one open downfield and instead threw a dump pass to Laurence Maroney:
Let's skip ahead to the Ravens' next drive and the adjustment the Patriots made on Derrick Mason.
Baltimore's second drive
Third-and-10, 38-yard line going in
In a fairly obvious passing situation, the Patriots went to the dime formation they used frequently the rest of the way, employing three defensive linemen, two linebackers and six defensive backs. Make sure to note:
* Meriweather, McGowan and James Sanders, all safeties, all were on the field at the same time. Both Meriweather and Sanders played so deep they were actually out of the picture on the CBS broadcast.
* Mason lined up by himself on the left side of the formation.
* Bodden, rather than giving Mason a wide cushion, crept up to the line of scrimmage at the snap to give Mason a bump before he could get into his route.
Mason went straight for the end zone. Bodden got a little bit of a bump on him and then passed him off, chasing a little bit but sitting back in zone coverage. McGowan, right in the middle of the formation, pursued Mark Clayton and Kelley Washington, the two receivers on the right side of the formation.
That left Meriweather and Sanders, the deep safeties, to pursue Mason. The wide receiver actually seemed to beat the coverage, but quarterback Joe Flacco threw off his back foot and gave Meriweather a chance to come all the way across the field and knock the ball away to save a touchdown:
Had the Patriots still been playing one safety deep rather than what Belichick called "split-safety" coverage, Meriweather wouldn't have been in the area to go knock down the pass: He would have been up in coverage and involved with either Clayton or Washington and nowhere near where the ball came down.
It's easy to see how playing an extra deep safety helps defend an opponents' best receiver -- but it also demonstrates how the Patriots won Sunday's game.
The split-safety coverage of the Patriots all but nullified Mason as a weapon. The coverage of Reed all but nullified Moss, too. All three times Moss caught the ball, Reed was uninvolved in the coverage. When Brady hit Moss for a touchdown, Reed was coming on a blitz from the outside -- and Brady only barely got the pass away before Reed was on him.
But the reason the Patriots won was because they had other weapons to employ. Nine different receivers caught passes for the Patriots on Sunday, including all four of the team's active running backs. One of the biggest plays of the game was a fourth-quarter pass Brady threw to running back Sammy Morris, split out wide, a pass Morris took for 14 yards that set up a field goal and pushed the Patriots' lead to six points.
(Reed, on that play, was playing in the middle of the field -- and Pro Bowl guard Logan Mankins went out to block him before he could get to Morris.)
The Ravens, on the other hand, needed a big play from Clayton at the end of the game -- and Clayton let a perfect pass from Flacco hit him right in the numbers.
That was the difference.
The Denver Broncos don't have a safety like Reed, but they do have one of the top cornerbacks in the NFL in Champ Bailey. It'll be interesting to see if they do what the Ravens did or if they do what the Jets did -- isolating their top corner on Moss while using their other 10 defenders to put extra pressure on Brady.