Most recently, he spent the past three years with the Rams and reunited with then-head coach Jeff Fisher, whom he worked with in Houston/Tennessee for almost a decade. The Rams finished ninth in yards per game (337) last year and 13th in points per game (20.6).
In all, Williams has led eight top-10 defenses and five top-five defenses: Tennessee (No. 1 in total defense in 2000), Buffalo (No. 3 in 2001 and No. 2 in 2003), Washington (No. 3 in 2005), and New Orleans (No. 4 in 2010).
A native of Excelsior Springs, Missouri, Williams spent three seasons (2001-2003) as the head coach of the Buffalo Bills before joining the Redskins as associate head coach/defensive coordinator.
2. So what’s he all about?: A disciple of legendary Bears defensive coordinator Buddy Ryan, Williams is known for employing an aggressive and flexible 4-3 front thatadapts to the strengths/weaknesses of the defensive personnel around him. Here’s what NFL.com analyst and former player Bucky Brooks wrote back in 2014 when Williams joined the Rams:
“From a schematic standpoint, Williams will use every front in the book. At his core, though, he's a 4-3 over/under guy. He implements a defensive audible system that adapts to offensive formations, allowing his guys to be in the best possible call on every down. Although the complex nature of the scheme puts a ton of pressure on the linebackers and safeties to make adjustments, it is a system that produces outstanding results when mastered.
“On passing downs, Williams certainly isn't afraid to mix in a variety of blitzes from exotic looks -- including some Okie fronts (3-4 or nickel 3-3 packages) -- as well as the standard 4-2-5 nickel front. He will order up Cover 0 all-out blitzes in any area of the field, which makes him the ultimate gambler as a play-caller. I've talked to many of his former players over the past few years, and they've raved about his aggressiveness and attack mentality.”
3. Reaching the Super Bowl: Williams, who spent three seasons with the Saints (2009-11), helped lift New Orleans to a Super Bowl with one of the league’s most improved defenses. After finishing near the bottom of several statistical categories, the Saints ranked fourth in yards per game (306.3) and seventh in points per game (19.2). New Orleans finished second in the NFL in takeaways and was known for shutting down opponents in the red zone.
4. Williams is a newcomer to the AFC North, but he’ll find at least one familiar face when he formally arrives in Cleveland. He coached alongside current Browns senior offensive assistant/wide receivers coach Al Saunders from 2004-07 when the pair worked under former Redskins coach Joe Gibbs.
5. Williams has worked with some of the league’s best defensive players, including Jevon Kearse and John Thorton in Tennessee; the late Sean Taylor in Washington; linebacker Jonathan Vilma, safety Roman Harper and the late Will Smith in New Orleans. He was also key in getting the most of former Rams linebacker James Laurinaitis and 2014 first-round draft pick Aaron Donald, who has emerged as one of the league’s best defensive linemen.