Shane Williams has scored more tries than any other Welsh player and sits fourth on the list of World Rugby’s all time try scorers.

He was named the best player in the world in 2008 and almost helped his country stun New Zealand in the World Cup semi-final in 2011.

But according to the popular winger, none of that compares to what Williams and his Welsh teammates achieved twice, in 2005 and again in 2008, winning the Six Nations and claiming the Grand Slam by beating England, Ireland, Scotland, France and Italy in the span of eight weeks.

“Winning the Grand Slam is one of my highest achievements,” he says, speaking exclusively to sports betting firm Betway. “In ’05, that Grand Slam came out of nowhere. We weren’t expected to do particularly well in that Six Nations.

“We played tough rugby, we defended our hearts out. It was almost like a movie, winning that Six Nations, to be perfectly honest. That’s up there with the best of them.”

“Then 2008 was a great Six Nations for me personally, because it was when I probably played my best rugby for Wales. We won the Grand Slam, I won player of the tournament and then went on to win IRB World Player of the Year. That was a huge Six Nations for me, I absolutely loved it.

“Both of those rank in the top, top rugby achievements, I’ve got to be honest. It doesn’t come around that often, so I’m very honoured to have done it twice.”

Williams was a part of many great Wales teams over the course of his 11-year international career, but there was something that set those two Grand Slam-winning squads apart from the rest.

“It was just self-belief,” he explains. “I played in Wales teams that probably hadn’t given themselves enough credit, especially the players.

“We had some great players, but collectively at times we let ourselves down. Physically and skilfully, we were always up there with the best, it was just sometimes we didn’t quite believe in ourselves.

“And I think that was the difference in those Grand Slams. We backed ourselves, we backed our physicality, we were mentally tough, and we had a strong enough squad to get us through the tournament unscathed, and that was the difference.”

France is the only undefeated team remaining in this year’s Six Nations, after defeating Italy and Ireland in the opening rounds.

Since the tournament became the Six Nations with the introduction of Italy in 2000, a Grand Slam has been won in 11 of 22 years – Wales have four, France have three, while England and Ireland have two each.

“It’s extremely hard to win the Grand Slam,” says Williams. “As people who watch the Six Nations know well, it’s such a short turnaround, it’s only five games, you’re only playing five different teams. Surely it’s not difficult to win every game? I can assure you it is.

“You’ve really got to be on top of your game for the full tournament. The level of competition is so tight. One mistake in any international match and you lose the match, and then obviously your chance at a Grand Slam is over.

“You’re playing against some of the best teams in the world, some of the best players in the world. You’ve got to have a bit of luck along the way, you’ve got to make sure you don’t get any injuries, your discipline has to be on point.”

Wales face England in a crucial round three clash on Sunday morning (Australian time). The winner of that match will then get to play France in the following weeks in a fixture that could decide this year’s champions.

While France remain in the box seat to win the competition and potentially claim the Grand Slam, Williams knows anything can happen in a tournament as tight as this.

“You need a massive amount of luck to win the Six Nations,” says Williams. “Just little

decisions, a referee perhaps being a bit lenient on a decision, a referee getting it wrong, the luck of a bounce, or a mistake made by the opposition.

“Even players getting injured when you’re meant to be playing against them. Anything, any kind of decision like that, you take them all day long, whether it’s to the detriment of another team or it benefits you.

“Sometimes you find that you get on the referee’s right side, and sometimes your team’s annoying the ref, and the captain is not quite getting in his own way and decisions go against you. The problem is, when these decisions don’t go your way, it’s almost a snowball effect.

“You start to lose discipline, other players in your team that lose discipline. All these factors count, they really do.

“It’s all about doing whatever it takes to win.”

This article is a sponsored post by Betway.