Before Shaun Edwards, there was David Ellis.

But like Edwards, he coaches union, specifically defence.

And for more than a decade, Yorkshireman Ellis held the job that Edwards has now; defence coach for the French national team.

During his time in the French set-up, Ellis was part of five Six Nations wins, three Grand Slams, and runs to the semi-final and final of the 2007 and 2011 World Cups respectively.

He has also held positions at Racing, Bordeaux, Castres, Brive and Lyon, and most recently spent time with Toulouse in preparation for their Champions Cup quarter-final win over Ulster in September.

England's Six Nations defence looks a lost cause after defeats by Scotland and Wales in the first three games. By contrast, France have it all to play for, riding high on confidence and victories over Italy and Ireland.

But Ellis says England can flip the formbook and knock the strut out of France's young, exciting team on Saturday at Twickenham. Here's how.

Win the whistle war

England's disciplinary record has come under scrutiny so far in the tournament, after they gave up 41 penalties in their first three games.

But France have their own problems. Mohamed Haouas' red card - for a haymaking right hand to Scotland flanker Jamie Ritchie's nose - arguably cost his side last year's title.

They picked up four yellow cards in the 2020 Six Nations, more than any other team, and Bernard le Roux's sin-binning meant last month's win over Ireland was narrower than it needed to be.

"Without a doubt, discipline is something that can let France down," Ellis told BBC Sport.

"They are a young side, relatively inexperienced, and when the opposition build pressure on them, they can infringe. It is an ongoing thing with the French.

"Even when I was involved with the French team, before emphasising any organisational aspects, individual discipline was the number one factor."

Target midfield

Virimi Vakatawa is back from injury and straight into the French XV. Strong and fast, he can find holes or create them. But, while England go with an established partnership in Owen Farrell and Henry Slade, Vakatawa and Gael Fickou have paired up in a starting midfield only five times previously.

And neither are specialists. Both have also done stints on the wing, Vakatawa at the start of his Test career, Fickou more recently.

"There is a question mark around midfield," explained Ellis.

"France have swapped and changed with Fickou out on the wing, and then back in centres. Vakatawa has been a staple at centre recently but he is a converted wing. Defensively, there is a weakness there.

"And, if and when Romain Ntamack comes off the bench, he is not the best defensive fly-half in the game."

Beware dangers of Teflon Dupont

Antoine Dupont's sniping power around the fringes and skilful hands have been one of the engines of France's revival.

The 24-year-old scrum-half is arguably the best player in the world right now, earning fulsome praise from England counterpart Ben Youngs and New Zealand nine Aaron Smith.

Eddie Jones said he would settle for Dupont having merely a good, rather than exceptional, game.

He said: "We'd like Dupont to have a tidy game, do all the simple things well, but not any of the special things.

"If we can keep him in a little box, then it will be a good result for us."

Second row Maro Itoje did an effective job of hassling Ali Price and Kieran Hardy in the games against Scotland and Wales respectively, albeit at the cost of several penalties. Will he be given the same mission against France?

"Ireland did a good job on France, and part of that was taking care of Antoine Dupont," said Ellis. "They put pressure on him so he didn't have any space to develop the quick style of play he likes."

Kick with caution

On France's last Six Nations trip to Twickenham in 2019, England ran away to a thumping 44-8 win as they kicked into acres of space behind the visiting defence.

Their full-back this weekend is Brice Dulin, who stands only 5ft 9in tall. But Ellis thinks England shouldn't be tempted to launch an aerial assault Dulin's way.

"You would be wasting your time," Ellis said.

"Dulin, alongside Dupont, has been France's outstanding player. I remember when Racing played the Heineken Cup final against Saracens in 2016. Richard Wigglesworth put up a load of box kicks, the weather wasn't good, Dulin was bombarded all the time... and he took everything.

"He is one of the best in the world under the high ball, his size doesn't come into it. When he leaves the ground, he commands the air."

Finish well in the front five

France have a grizzled forward pack to go with a glittering backline. But some of their strength in the front five has been sapped by illness and injury.

Second row Le Roux is missing and replaced by Romain Taofifenua, making only his third start in as many years for France.

"When France play their best front five, you are not going to get much out of them," said Ellis.

"Julien Marchand is the prototype for a modern-day hooker - a great runner and ball-handler who can jackal and turn the ball over in defence.

"With Le Roux and Paul Willemse, it is like having two additional back-row forwards. They carry really well and hit hard in defence.

"But when any other second row is in there, the wheels start coming loose.

"And in the second half, when the changes go into the front row, there is doubt over whether the replacements are going to be able to do as well."