Just to put this defensive thing in context look at the numbers and comments here..................... from BBC Chief Sports Writer:-

"This is not an extravagantly gifted Welsh team. Not once in this championship have they scored more than 26 points in a game. England scored 32 or more on four occasions.

Only Italy created as few tries. England scored 14 more. It all matters less than the paltry seven that Wales conceded, almost half as many as Eddie Jones's team.

Gatland has been loyal to his key lieutenant, defence coach Shaun Edwards. You can see why. Each of the three Slams has been constructed around an immovable Edwards defence.

During this 14-match winning streak they have shipped just 19 tries and an average of 13 points per game. It is why Scotland head coach Gregor Townsend called it the best defence in the world and it is why, more than any other single factor, why Cardiff was cavorting again on Saturday night.

It took Ireland until the 82nd minute to breach it, when they had scored at least 20 points in their previous eight Six Nations games. An England side that had conjured up four tries in Dublin and three in the first half-hour alone against France were kept to just one here in their defeat three weeks ago."