Former Raiders defensive tackle Sam Adams agreed Sunday to a four-year deal with the Buffalo Bills.

	Adams

The Bills added an anchor to the defense that could make their two-year investments in linebackers that much better. Financial terms of the deal were not available.

Adams had been negotiating exclusively with the Bills for the past three weeks, and this weekend was going to be critical. Bills general manager Tom Donahoe wanted to have a deal wrapped up by this weekend or he was going to move on to other linemen, while Adams wanted to have a deal wrapped up by the weekend or he was going to start talking to other teams, including the Ravens.

Adams was a member of the Ravens' Super Bowl team two years ago.

The deal came together Sunday when Adams agreed to an incentive-laden deal that rewards him for playing time and performance.

"Now, I'm going to work to be the player they want me to be,'' Adams said. "I think this move in signing me will help get this team to the Super Bowl.''

The Bills have had a great offseason in improving the defense. Last year, their main free agent signing was middle linebacker London Fletcher. This year, they brought in Takeo Spikes and Jeff Posey to be the outside linebackers.

But not having a second huge defensive lineman, it would have allowed opponents to let their guards and centers go after the linebackers. Adams fixes that problem and will play next to defensive tackle Pat Williams.

Williams and former Bills defensive tackle Ted Washington formed one of the better inside units in the NFL before the Bills let Washington move to Chicago.

Williams, Adams and Washington are close friends. In fact, Adams is considering living in Washington's home in Buffalo.

John Clayton is a senior writer for ESPN.com.