Great football teams usually have at least a good defense.
In fact, last season, the champions of each "Big Six" conference ranked among the nation's top 30 in total defense. Five ranked among the top 10: Ohio State (No. 1), USC (No. 2), LSU (No. 3), Virginia Tech (No. 4) and West Virginia (No. 7). The other was Oklahoma (No. 26).
Players come and go, so a defense that struggled in 2007 won't necessarily have the same problems in '08. But for many teams, ensuring improvement and building a championship-caliber defensive unit is predicated on bolstering at least one area. Some teams need to get better up front. Others need to shore up the linebackers or the secondary. But some face bigger reconstruction projects than others.
Here's a look at a few defenses with problem areas.
? Notre Dame: The Irish use a three-man front. Good thing. The depth up front is extremely thin. Notre Dame ranked 97th nationally in run defense and sacks last season, and they lost end Trevor Laws - who led the team in tackles and sacks. A possible replacement is junior Morrice Richardson, who had seven tackles as a linebacker in '07. No returning player had more than 2.5 sacks. On the positive side, nose tackle Ian Williams had a solid freshman year.
? Miami: Sacks leader Calais Campbell left early for the NFL. Tackle Teraz McCray completed his eligibility. End Courtney Harris is out for the season with an Achilles injury. Tackle Josh Holmes was lost to injury, too. End Allen Bailey, a projected starter, may miss the beginning of the season with a torn pectoral.
? Oklahoma State: Tackle Jeray Chatham is the only returning starter among the front four. Last year, he accounted for 1.5 of the Cowboys' 22 sacks. The Cowboys were no better than average against the run and in rushing the passer in '07. Unless a few newcomers emerge, there is no reason to believe they will be much better in '08.
? Nebraska: The Huskers allowed more than 232 rushing yards per game last season, so it might not seem like a big deal that the top four linebackers from '07 are gone. But what does that say about the guys who played behind them? The Huskers are looking for help at linebacker from converted running back Cody Glenn. Tyler Wortman, a former walk-on who had nine tackles in '07, also is a possible starter. The leading returning tackler among linebackers is Phillip Dillard, who managed 37 stops a year ago. The Huskers figure to be better defensively under coach Bo Pelini, but he has his work cut out rebuilding the linebacker position.
? Alabama: Rolando McClain is back. So much for the good news. The linebacker situation was so dire that Jimmy Johns was moved there from running back during spring ball and had a shot at winning a starting job. Instead, he was arrested on drug charges and kicked off the team. Then, Ezekial Knight, who had 64 tackles last season, was lost because of a medical condition. Prince Hall, a starter as a freshman, has been suspended indefinitely and his status is uncertain. The Tide may rely on true freshmen to play immediately.
? Virginia Tech: The situation isn't quite as dire in Blacksburg, but losing last season's top two tacklers ? Xavier Adibi and Vince Hall ? has to cause some concern. Cam Martin is a returning starter, but seniors Brett Warren and Purnell Sturdivant likely will be full-time starters for the first time. Last season, they combined for 55 tackles.
? Florida: The Gators' secondary is shaky ? kind of like some politicians' ethics are shaky. Florida gave up 19 touchdown passes while ranking 99th nationally in pass defense last season. There could be a huge void at strong safety. Expected starter Dorian Munroe was lost for the year with a knee injury. Backup John Curtis was, too. Backup Jamar Hornsby was dismissed from the team for credit card larceny, and heralded recruit Dee Finley is academically ineligible. Major Wright is a returning starter at free safety, but may be better-suited for strong safety.
? Texas: In allowing 23 touchdown passes and an average of 278 passing yards per game, the Longhorns' pass defense was among worst in the country last season. Texas will have three new starters in the secondary. Both likely starters at safety, Earl Thomas and Ben Wells, are redshirt freshmen.
? Boston College: Free safety Jamie Silva earned All-America honors last season and cornerback DeJuan Tribble had 11 interceptions in the past two seasons. Yet BC was painfully vulnerable to the pass in '07. Now, Silva, Tribble and cornerback Raji Morris are gone. Senior strong safety Paul Anderson is the only returning starter.
What four cities of the same name but in different states are the location of Division I-A college football programs. (Answer at the end of the column.)
Where did these athletes-turned-actors play college football? (Answers at the end of the column.)
? North Carolina junior wide receiver Hakeem Nicks is aiming for a big season. He's said his goal is to catch at least 10 touchdown passes and post more than 1,200 receiving yards. Then, he said, he will consider early entry into the NFL draft.
? Colorado tight end Riar Geer pleaded guilty to third-degree assault, a Class 1 misdemeanor, stemming from a brawl in March. In exchange for the guilty plea, prosecutors dropped a second-degree felony assault charge. Greer could face as much as two years in jail or could get probation. His sentencing has been scheduled for Aug. 18. If he gets probation, he could return to the team. Colorado coach Dan Hawkins does not allow felons on the team, but has a policy of giving players convicted of lesser charges a second chance.
? West Virginia junior college recruit Tevita Finau, a four-star defensive end prospect, still has some academic work to do to become eligible for this season. It might be that Finau has to finish up at a junior college this fall, then enroll at WVU in January.
? Oregon players have set up a Todd Doxey Memorial Fund to help cover funeral expenses. Doxey, 19, a redshirt freshman safety, drowned July 13 in a river near the Oregon campus. To donate: Todd Doxey Jr. Memorial Fund, Washington Mutual Bank, 4415 Imperial Ave., San Diego, CA 92113.
? Georgia athletic director Damon Evans said he's anticipating that venerable broadcaster Larry Munson will return to the radio booth. Munson, who would be entering his 43rd season calling Georgia football games, had blood clots removed from his brain last April.