The Bucs have finished last in the division each of the past five seasons and are counting on the former Atlanta Falcons coach to construct a defense that will help Koetter and young quarterback Jameis Winston's chances of transforming the struggling franchise into a playoff contender.
Koetter became the club's fourth coach in seven years last week, replacing Lovie Smith. His first order of business was to hire Mike Smith as defensive coordinator.
The close friends originally worked together as assistants in Jacksonville. They reunited for the first time in Atlanta, where Smith compiled a 66-46 record in seven seasons as head coach from 2008-14, the last three with Koetter serving as Falcons offensive coordinator.
Smith interviewed for at least one NFL head coaching vacancy this month. When he didn't land a position, he welcomed the opportunity to work for Koetter in Tampa Bay, saying it's the only place he would have considered becoming defensive coordinator, the title he held in Jacksonville when Koetter joined the Jaguars as offensive coordinator in 2007.
One reason is his relationship with the Bucs coach. Another is Winston, the No. 1 overall pick in last year's draft.
''In this league, it's about quarterback play, there's no doubt about it. Jameis had an outstanding rookie season. I think he's going to be a great quarterback,'' Smith said. ''When you have a quarterback, that makes your chances of being successful much more.''
Smith believes his familiarity with the NFC South - especially the quarterbacks the Bucs face twice every season - figures to be helpful.
''Let me say this about the NFC South: Look at the four teams. Look at the four quarterbacks. Is there any other division in the National Football League that has quarterback play like you have here in the NFC South?'' Smith said, referring to Winston, Carolina's Cam Newton, Atlanta's Matt Ryan and New Orleans' Drew Brees.
''So as the defensive coordinator, you're going to have some sleepless nights and some long game planning days to prepare for the other quarterbacks we're going to be playing,'' he added.
''But the great thing about it is that those defensive coordinators on those other teams are going to have the same thing with Jameis and Dirk putting together a game plan.''
The Bucs went 8-24 over the past two seasons while playing Lovie Smith's version of the Tampa 2 defense. Without offering many details, Mike Smith said his defense will be ''flexible ... simple for our players, and complex for the quarterbacks and opposing coaching staff.''
''In this day and age, you have to give different looks. You can't line up in the same look and same front every time, so we're going to have a lot of flexibility and we're going to identify what the players are capable of doing,'' Smith said.
''That's what coaching is all about,'' the defensive coordinator added. ''It's about putting them in a spot where they can be successful and be the best version of themselves.''
The Bucs allowed the 10th-fewest yards in the league this season, but ranked 26th in the most important defensive statistic - points allowed.
''Ultimately as a defensive coach you're going to be judged on how many points you give up. That's the bottom line,'' Smith said. ''It's not yards. It's not rushing yards, it's not passing yards, it's not sacks. Ultimately it's about keeping them out of the end zone.''
Jacksonville's defenses ranked among the league's best under Smith from 2003 to 2007. During his last season with the Jaguars, he made quite an impression on Koetter, then in his first season as a NFL coordinator.
''We were both in the press box that year. I'd never seen anybody like Mike Smith before,'' Koetter said after hiring his former boss last week.
''We had a good year, but we lost to New England at New England in the second round of the playoffs,'' the coach added. ''Mike was hired by the Falcons the next year. We were never as good after we lost Mike Smith.''
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