The biggest moves the Bears made on defense -- or at least the ones getting the most attention -- were the changes on the coaching staff. Rod Marinelli was hired to coach the defensive line, and Lovie Smith will call the plays instead of defensive coordinator Bob Babich. But I discussed the two biggest personnel changes on defense -- the acquisition of linebacker Pisa Tinoisamoa and the loss of safety Mike Brown -- with Bill Barnwell, the managing editor of Football Outsiders. Its mean projection gives the Bears a 49 percent chance to have 11 or more victories -- the highest figure for any NFC club.
First, I asked Barnwell about Tinoisamoa, who's projected to be the starter on the strong side after signing a one-year contract. The St. Louis Rams cut him loose after they failed to trade him. He became the first rookie in franchise history to lead the defense in tackles when he played for Smith and Babich in 2003.
''It really depends on Tinoisamoa and how he fits into their scheme and how quickly he catches up on things,'' Barnwell said. ''I understand he's had experience in the system.''
Football Outsiders looks at a stat it calls the ''stop rate,'' the average yards for running plays when the linebacker makes the tackle. It's not a perfect system, but it has other stats, one of which is called ''defeats,'' defined as the number of times the defense makes a play behind the line of scrimmage, creates turnovers or stops the offense from gaining first downs on third or fourth down.
Tinoisamoa, who played weak side for the Rams last season, was credited with 48 stops, 32 fewer than Lance Briggs. Tinoisamoa ranked 93rd out of 99 linebackers against the run. But as Barnwell pointed out, these statistics can change depending on the team and the system.
''The Rams didn't have a great defense,'' Barnwell said. ''You look at his run numbers, and they were atrocious. He made a lot of tackles, but they were seven or eight yards from the line of scrimmage. You have to put the scheme in context. He could be better this season.''
Tinoisamoa will have more talent around him this season, and it's reasonable to expect he'll be a different player. Of course, the Bears expected the same with Adam Archuleta in 2007.
