RIVER FALLS, Wis. — Derrick Thomas was one of the best pass rushers of a generation, a dynamic, relentless force who left quarterbacks woozy and mumbling to themselves. Teamed with defensive end Neil Smith, he made the Chiefs one of the NFL’s best at getting to the quarterback.

Oh, how things have changed in Kansas City.
Once sack happy, the Chiefs have become sad sacks, coming off a season in which they set the standard for pass-rushing futility: 10 sacks. Thomas had at least that many seven times in 11 seasons and nearly matched it in a single game, putting Seattle’s Dave Krieg on his back seven times on Veterans Day 1990.
So as the final touches are being put on Thomas’ Hall of Fame bust this week, the Chiefs begin their quest to find a way, any way, to get some kind of pass rush. They’ve retooled the defense, brought in new players, switched old players to new positions and hired a new defensive coordinator.
“We have to create some havoc in the backfield,” Chiefs coach Todd Haley said Monday. “Whether it’s leading the league in sacks or just creating some chaos back there, it has to happen for us to play the type of defense we want to play.”
Leading the league in sacks might be a stretch. There’s no reason the Chiefs shouldn’t be better, though.
The team switched defensive schemes, eschewing a four-man front for a 3-4 alignment, allowing the outside linebackers to provide the pass rush. But this isn’t your basic 3-4 defense. New defensive coordinator Clancy Pendergast has one of the deepest defensive playbooks in the NFL, filled with multiple fronts and blitz packages.
Under Pendergast, who worked with Haley at Arizona, the Chiefs might line up with a five-man front one down, a two-man front the next. Blitzes could come from anywhere and everywhere. The key is keep the opponent from knowing what’s coming, as new Chiefs quarterback Matt Cassel found out when he led the Patriots to a win over Arizona last season.
“His defense is a very elaborate scheme,” Cassel said. “They are blitzing from all the place and are doing a lot of things out there, giving us a lot of different looks. It’s definitely challenging from the quarterback position when you’re getting different looks every play.”
The personnel will be different, too, both in new faces and new places.
The Chiefs used the third overall pick of this year’s draft on LSU’s Tyson Jackson, a strong, quick defensive end. Kansas City later picked up versatile defensive lineman Alex Magee with a third-round pick out of Purdue.
The Chiefs also brought in some veteran help, picking up linebacker Mike Vrabel from New England in the Cassel trade and signing former Dolphins and Cowboys linebacker Zach Thomas. Neither is a sack expert and both are older, but they should provide leadership and support for the younger players.
Kansas City also is hoping a switch in positions will spark Tamba Hali and Glenn Dorsey.
Hali was a steady complement to Jared Allen his first two years in the league, producing 15.5 sacks. Once Allen was traded to Minnesota, teams started to pay more attention to Hali and his sack total dropped to three last season. Down about 20 pounds from last season, the Chiefs hope he — and former lineman Turk McBride — can be more productive by building up a head of steam from outside linebacker.
Dorsey, the fifth overall pick in 2008, never really lived up to his potential last season, recording 50 tackles and one sack. This season, the Chiefs have asked him to drop weight and moved him from the interior to defensive end, hoping the pass-rushing ability he showed at LSU will come through.
The changes look good on paper and seem to be working so far in the limited context of training camp. The real gauge, though, will be once the games start.
“Hopefully, we can make this work, but it’s a lot of talk,” Thomas said. “It’s early. Everybody thinks they’re going to win a lot of games this year, but that doesn’t happen. Hopefully, we’ll be the team that does.”