Stacy Boit,

Before last year’s Women’s Six Nations Grand Slam decider, England had conceded 29 points in four games.

The world champion Red Roses, who are on a record 37-game winning run, travel to Bordeaux on Sunday for this year’s finale against France having conceded 76 points.

In their past two games, Wales and Italy – neither of whom reached the Rugby World Cup quarter-finals – scored nine tries between them, with both earning a rare try bonus point.

France, who scored 42 points but still lost last year’s Grand Slam decider at Allianz Stadium, bagged 69 points on Saturday to punish Scotland’s leaky defence.

England’s attack remains slick and worthy of a fifth straight Grand Slam but their defence has come under scrutiny, giving Sunday’s showdown a sense of jeopardy that few predicted at the start of the championship.

England started the campaign by conceding 12 points against Ireland at Allianz Stadium and seven against Scotland at Murrayfield.

Their defence remained hard to beat until injuries continued to mount for head coach John Mitchell, who was already without four World Cup winners because of pregnancy.

Thirty players have featured – five of whom have earned their first caps.

A shortage of locks has seen 19-year-old Haineala Lutui, usually a back rower for club side Loughborough Lightning, step into the second row, while flanker Abi Burton, who was capped last year, has also filled in out of position.

Nine of the forwards who played in the World Cup final were unavailable against Italy in Parma.

“We are going through a lot of changes and the players are still learning and growing,” Mitchell said on Saturday.

“I am trying to explain to the younger players how important it [learning new positions] is, and they are only growing. They don’t understand how important it is at this point in their careers.”

It takes time to learn individual roles within a defensive system and mistakes have resulted in England conceding, on average, 4.8 more points per game and 0.8 more tries than in last year’s campaign – which includes the epic 43-42 Grand Slam decider.

Before England’s toughest fixture against their title rivals, missed tackles are up by 3.45 per game, while only 5.5 tackles per match have been dominant this campaign, down from 12.4 last year.

The improvement of the other teams in the championship has also played a part.

“We have conceded more points than probably we wanted to,” said Burton.

“We just need to tighten up those little leaky holes that we had against Italy.

“We know that France are going to come at us in any which way, shape and form.

“Naturally when there is change, there will be more knowledge in some places than the others, so it about bringing everyone up to speed.”