Wales v Ireland: Dan Biggar and Johnny Sexton again aim to be perfect 10

It might be a new Six Nations tournament but old heads remain the order of the day for Wales and Ireland in 2021.

For their competition opener, Ireland will have more than 700 caps for the starting side.

Even more experienced will be the starting Wales XV with a combined total of 874 caps making that a national record.

You just have to look at the respective number 10s to prove that if you are good enough you are young enough. That is the wisdom opposing coaches Wayne Pivac and Andy Farrell are applying this weekend.

In the red corner, you have 31-year-old Dan Biggar who made his Wales debut in 2008 and has scored 458 points in 87 Tests.

In the green corner, is the 35-year-old captain Johnny Sexton who has amassed 865 points in 101 internationals for Ireland and the British and Irish Lions.

That is 1,323 points in 188 Tests. Impressive.

The pair know each other very well having been rivals as well as team-mates on the 2017 Lions tour of New Zealand.

They are also similar characters. Driven and determined with the potential to sometimes demonstrate extreme emotions that are close to the edge.

What some will call petulance others call passion, with experienced England referee Wayne Barnes charged with handling the feisty foes this weekend.

What is not in doubt is that they are both born winners with Grand Slams, Six Nations, Champions Cup and Lions series titles to their names.

Wales kicking coach Neil Jenkins is a good judge of the two players, having worked with both on the Lions tour of New Zealand.

There is also a little matter of 1,090 points in 91 Tests for Jenkins. So he knows a thing or two when it comes to outstanding outside-halves.

"You've got two very good 10s going against each other who are both determined to win and get their nation off to a good start," said Jenkins.

"There's no doubt there will be some niggle and edge, but it's got to be disciplined edge too.

"Dan is an incredible player for us. He keeps himself in tip-top condition, his hunger is incredible, constantly wanting to lead our team.

"I've known him for a long time, since he was a kid in the academy, and he's always had that attitude about him.

"Maybe it's a bit of cockiness, not arrogance, but it's positive. He knows he can go out and do the job. He's been exceptional for us. I like to think he's going to have a good game again."

"Johnny is the same. He's an incredible player and has had a fantastic career. He's still going - age is only a number - his body and his head (are still good).

"He has shown what he can do at this level and is a serial winner. He's a fantastic player."

Biggar knows Sexton and his Irish half-back partner Connor Murray well, having faced them many times with Ospreys and Wales and toured with the Irish pair on that Lions tour four years ago.

"It's very difficult to know what to say about them," said Biggar.

"They are two good players, experienced and have been there in big moments.

"They've won championships and won big games for club and country. They probably don't need a huge amount said about them. They're very good operators and have played a lot together and formed a good partnership.

"They'll be looking for their lead guys in front of them to do a good job for them first. On the flip side, we're hoping our lead guys in front of us can do a job of nullifying them."

Biggar is actually a relative young buck, with Sexton four years his senior. The Northampton fly-half does not feel players should be consigned to history once they reach 30.

"There's no sell-by date on us as players," said Biggar.

"It's difficult to just say 'when a player hits 30, discard them'. In a group that's looking to develop youngsters as well, that blend of experience and youth is important.

"You don't want your whole team full of youth and you don't want your whole team full of old guys like myself! It's important to have a good blend."

So how does Biggar feel as he prepares for his 13th year of international rugby?

"I do feel older! It evolves every year. I've been around the squad for a while and it's quite nice to have the core of our team at the moment being experienced with some fresh-faced talent.

"You look at (Wales and Gloucester wing) Louis Rees-Zammit and boys like that coming in, freshening the squad up and keeping you on your toes.

"The Six Nations always feels different to an autumn or to a summer tour. It will miss out on crowds, which is part of the whole weekend for players, supporters and everyone.

"I feel good and like I'm still contributing in some way, shape or form. I'm hoping that come Sunday afternoon I can still offer a bit on the field.

"I haven't played a huge amount of rugby over the last month, so it's been good to rest a couple of niggles and get a couple of things right.

"I'm hoping it'll be super-charged from us and I am looking to put a marker down early doors."