Nickels and dimes added up

Patriots made valuable use of defensive packages

Bill Belichick and his Patriots had it made in the shade Sunday with their convincing 30-21 win over the 49ers. (Matthew J. Lee/Globe Staff)

SAN JOSE, Calif. - Safety Rodney Harrison said that when the Patriots defense first took the field in Sunday's 30-21 victory over the San Francisco 49ers, the unit was playing tentatively, dipping its collective toes into the water like a first-time swimmer.

You can't blame the Patriots for being a little apprehensive. The last time they'd taken the field, in a 38-13 loss to the Miami Dolphins Sept. 21, they were swept away by a wave of "Wildcat" spread option plays. Plus, they entered the game well below sea level in third-down defense. Prior to Sunday, New England (3-1) ranked second to last in the NFL in that category, having allowed opponents to convert on 18 of 37 tries.

But facing the ever-imaginative Mike Martz, San Francisco's offensive coordinator, the Patriots put their bye week to use and showed some imagination of their own on defense, unveiling variations of their nickel and dime packages that put more speed on the field and helped them hold San Francisco to just 1 of 9 on third downs.

San Francisco's lone third-down conversion came on its first touchdown drive, when a defensive holding call on Deltha O'Neal allowed the 49ers to convert a third and 2.

"The two things statistically that have hurt us the most in our first three games have been our third-down defense and our red area offense," said Patriots coach Bill Belichick. "It was good to be able to get the ball into the end zone. It was good to be able to have, statistically, a better day on third down.

"Those two things helped us. Hopefully, that will help us going forward because it's hard to win games if you're not efficient."

On seven of the nine third downs the 49ers had, the Patriots, who play a base 3-4 defense, went with a dime look. The team had two different dime packages. One had a defensive lineman (Jarvis Green or Mike Wright), four linebackers (Mike Vrabel and Pierre Woods outside and Adalius Thomas and rookie Gary Guyton inside), and six defensive backs (Harrison and James Sanders at safety with O'Neal and Ellis Hobbs at cornerback, plus situation safety Brandon Meriweather and rookie Jonathan Wilhite, who played as the slot corner).

The other package replaced Woods with either Green or Wright, giving the Patriots two defensive linemen and three linebackers. Of the 48 plays (30 passes) the 49ers ran, the Patriots were in a dime defense for 25 of them.

New England also gave San Francisco different looks in its nickel package, sometimes going with four down linemen and two linebackers, usually Thomas and rookie Jerod Mayo, or keeping Vrabel on the field and giving a 3-3-5 look.

Belichick praised the work of the players in the nickel and dime schemes and said the sub packages, which were classic pieces of Patriots game-planning, crafted during the bye week, were specific to stopping the 49ers.

He pointed out that the third-down defense was aided by the Patriots' ability to slow the run and create third-and-long situations and the New England offense's ability to monopolize the ball and score points, forcing the 49ers to play from behind.

"Those two factors helped to push it toward a passing game and more of a one-dimensional game," said Belichick. "So, we really only defended one thing and that helped us on third down and on fourth-quarter, two-minute situations."

San Francisco running back Frank Gore, who entered the game leading the NFL in yards from scrimmage, had 12 carries for 54 yards and four receptions for 24 yards and a score. However, Gore didn't come close to gouging the Patriots the way Dolphins running back Ronnie Brown had two weeks earlier.

"I think every week your No. 1 thing with any NFL defense is the fact that you have to take away the run and not give them an opportunity to pass the ball as well as run the ball, especially with a guy like Mike Martz," said Harrison. "His offense deals with so much trickery - deep routes, intermediate routes, the screen game. It's so tough to try to dictate what he's trying to do.

"Our point of emphasis was to take away the run, No. 1, and then be very competitive on the passes down the field. Initially, we weren't, but as we calmed down, we played a lot better."

The secondary, which allowed back-to-back touchdown passes by 49ers quarterback J.T. O'Sullivan in the first quarter, finished with three interceptions. That was one more turnover than the Patriots had generated in their first three games.

Harrison said getting hands on footballs was a point of emphasis in the week leading up to the game because the Patriots knew O'Sullivan liked to scramble and throw.

Unlike against Miami, the Patriots were able to make in-game corrections and adjustments, an indication that the meltdown against Miami may have been an aberration rather than a cause for alarm over a defense that is both advanced in age and unproven in its personnel.

"When you come out of a game like Miami where it's almost like . . . things are just blurring by you, and then coming back out there and making our adjustments [Sunday] - players talking to the coaches and coaches talking to the players and making those adjustments on the fly and then executing it - it says a lot about how we did our bye week," said Hobbs, who took the rap for both of O'Sullivan's first two TD tosses.

While the defense may have started out playing anything but swimmingly on Sunday, it finished with a Michael Phelps-like flourish. And without Tom Brady, the Patriots are going to need strong play from the defense to keep their heads above water.

Mike Reiss of the Globe staff contributed to this report.