He came to the Jaguars after making the Seattle Seahawks the stingiest defense in the NFL in 2012. While in Seattle, Bradley's schemes routinely stifled the 49ers.
In two games last season Bradley's Seahawks unit held them to only 26 points combined. They sacked San Francisco quarterbacks and perhaps more importantly, slowed down the rushing attack led by Frank Gore.
Bradley took his system with him to Jacksonville and he will be hoping it can again give him the edge. The scheme is built on a blended defensive front that looks like a 4-3, but often plays like a 3-4.
The two most important players are the de facto defensive ends. One is referred to as "Leo," the other as "Elephant."
The "Leo" is a hybrid pass-rusher, a combination of rush end and outside linebacker. He can drop into coverage or pressure the pocket.
The "Elephant" is a converted defensive tackle shifted out to end. He plays directly over the offensive tackle as a 5-technique and is responsible for two gaps against the run.
So while Bradley's defense is ostensibly a 4-3, on any play he can show two outside linebackers, simply by moving the "Leo" off the line, with three hulking interior linemen between them.
That is how Bradley assembles his front, but one of the key characteristics of his system is the way the secondary plays. Bradley emphasises size in the defensive backfield.
His cornerbacks are big and tasked with pressing wide receivers in bump and run coverage. They funnel all inside routes to a pair of punishing safeties.
This scheme worked wonders for the Seahawks when they hosted the 49ers in Week 16 last season. Gore had rushed for 131 yards in their first meeting, a 13-6 San Francisco win in Week 7.
But he was bottled up in Seattle, gaining only 28 yards. Perhaps more importantly, the Seahawks contained dual-threat Colin Kaepernick, something that has to be a priority for the Jaguars at Wembley.
Kaepernick gained just 31 yards as a runner and could not escape for the kind of big gains that usually kill the 49ers opponents.
He was also frustrated as a passer by Seattle's combination of press coverage and a consistent push on the pocket.
Can Bradley possibly repeat this formula on Sunday with the 0-7 Jaguars? So far his defense ranks last in the NFL in points and against the run.
The problem is simple. Bradley does not have the same quality personnel he had in Seattle.
For the Seahawks the "Elephant" was Red Bryant, a mammoth D-lineman who regularly draws two and sometimes even three blockers. In Jacksonville, Bradley has Tyson Alualu, who at 295 pounds lacks Bryant's size.
His "Leo" in Seattle was Chris Clemons, a tenacious and accomplished pass-rusher. The Jaguars feature veteran Jason Babin, long past his best, at this key position.
Bradley's Seahawks could also rely on arguably the best tandem of cornerbacks in the league. Richard Sherman and Brandon Browner both have the size and press skills to make this scheme work.
In Jacksonville, Bradley has enlisted journeyman Alan Ball at one corner spot. At the other he has Will Blackmon, a Seahawks castoff who is quietly impressing.
If Blackmon's unit has a chance at Wembley, its two best playmakers will have to dominate. Rookie safety Johnathan Cyprien and middle linebacker Paul Posluzny will both be key, particularly when it comes to spying Kaepernick.
Bradley doesn't have the pieces yet to make his system work. So he will have to get creative and add a few tweaks to keep the 49ers off balance, and give the Jags some hope.
image: © Joe Schlabotnik