Published 6 minutes ago I have never seen a team win a World Cup without a solid defence.
We talk about France having the best attack at this tournament but, now we are in the knockout stage, being able to stop goals is going to be as important as scoring them.
England, for example, will need to tighten up at the back compared to how they played against Croatia and Ghana. The games are going to be harder and closer, even for the leading teams - we are not going to see as many big scores.
There have been a lot of goals so far, more than at any other World Cup, but some defences have already impressed me and, when I think about the strongest, then maybe it's the Dutch who have the best one.
I really like the whole Netherlands back-line of Denzel Dumfries or Jurrien Timber, Jan Paul van Hecke, Virgil van Dijk and Micky Van de Ven, and almost all of them have just had very good seasons.
The only one you might say who was not at his best with his club team was Virgil but I would say that was more down to Liverpool's problems than his.
Virgil is still the leader of that Dutch defence and he has not just got talented players around him, they have got lots of pace and energy and physicality too.
He is 34, almost 35 now, but already we have seen some superstar attackers who are much older have a big impact at this tournament, and I feel he is also still at the top of his game.
Image source, Reuters Image caption, Van Dijk has played every minute of the Netherlands' three games at this World Cup
Virgil is a player I know very well. I know he has named me as his toughest opponent - he called me his 'bogeyman' because of the goals I scored against him - but we have got a mutual respect.
I would put him in my top three of toughest defenders I have faced too, along with Spain's Sergio Ramos and Portugal's Pepe, and we have had some great duels down the years.
In the past, my friends have shown me a funny picture of him which always makes me laugh - you can see it here below - where we are having a physical battle. I think I won it!
Image source, Getty Images Image caption, As well as winning this challenge, Giroud won the game too - scoring with a header in Chelsea's 1-0 win over Liverpool in May 2018
I have just chested the ball and look quite cool and composed, while Virgil is bouncing off me, and falling down like that.
I wish that happened every time we played each other - but it was maybe the one time in 10 that I won our duel and that's why it is funny. There must be many other pictures where he is up, and it is me down on the floor!
That photo was taken in 2018 and Virgil has had a few injuries since then, but he is still strong and of course he is still as clever and composed as ever.
This is probably his last chance to win a World Cup and I am pretty sure he knows his team are relying also on his leadership to go far in the tournament, which is the other side of what he brings.
As well as being captain, he is kind of the big brother of his national team now, the one who needs to show the path and set an example on the pitch, and I know he has got the character to deal with that being on his shoulders.
I still do not see the Dutch as being among the favourites for this World Cup but they have some talented players and maybe we should be talking about them more than we are. Whatever they do from here, though, Virgil is still the main man for them.
He is so experienced and has won so many trophies. He will know the Dutch have not reached the final at a World Cup since South Africa 2010.
Sixteen years is a long time, Virgil - so maybe it is time to put that right!
Image source, Getty Images Image caption, Rudiger (back) and Giroud were team-mates at Chelsea between 2018 and 2021
Another defender I am a big fan of at this World Cup is Germany's Antonio Rudiger, who was one of the toughest defenders I played with, let alone against!
I hated playing against him in training at Chelsea because he was the same as he is in a game - well, a little more careful and a little less crazy maybe, but he is still always pinching you and annoying you like that!
If he is in good condition, he is one of the best. He has not started every game so far but if he is fit, he is a good combination with Jonathan Tah at the back. They look strong together.
What is most important with any defence however is the balance of the team. It does not matter how good you are because you also need to have midfielders who are going to protect you. If you are open, and you are against pacy players, it becomes very difficult.
The Argentina midfield is really strong in that way, because they know they have to cover some ground defensively for Lionel Messi, who does not have the legs to do that.
Messi has never been the one chasing opponents, pressing wise, but that doesn't matter if behind him, their midfield is working hard without the ball to protect the backline.
Frenkie de Jong does that for the Netherlands and Brazil have the right balance in that way too with Bruno Guimaraes and Casemiro.
We had this with France when we won the World Cup in 2018 with our midfield of N'Golo Kante, Paul Pogba and Blaise Matuidi. They all worked hard, but if anyone left a gap then N'Golo compensated for it.
This time, France play with one more offensive player in there, so we will have to see if we can still try to score more goals than our opponents, without losing that cover deeper in the pitch.
I feel we can score goals any time in a game but if we can also protect our lead with a good defence, it's a massive asset for any team.
Olivier Giroud was speaking to BBC Sport's Chris Bevan
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Sources: BBC Sport
