Six Nations 2016: Title race 'wide open' - Jamie Roberts

Wales centre Jamie Roberts believes the 2016 Six Nations title race is "wide open" despite their opening draw with Ireland.

Roberts and his team-mates fought back from 13-0 down on Sunday in Dublin, a day after England saw off Scotland and France narrowly beat Italy.

"The championship is wide open and if we win the next four games, we will be in with a shout," said Roberts.

Captain Sam Warburton said Wales' four remaining games are "must win".

Warren Gatland's side host Scotland on Saturday and France on Friday, 26 February before going to Twickenham to face England on 12 March and returning to Cardiff to take on Italy on Saturday 19 March.

No team has ever won the Six Nations after drawing their opening game.

But British and Irish Lions centre Roberts says having taken the 2013 title after losing their opening game to Ireland in Cardiff offers encouragement in 2016.

"We won the championship in 2013 after losing the first game and we all remember what happened last year on that last Saturday after teams lost a game as well," said Roberts.

However, the 29-year-old Harlequins centre is expecting Scotland to provide another tough test when they meet at the Millennium Stadium on Saturday.

Roberts believes Scotland were "desperately unlucky" to lose to Australia in the 2015 World Cup quarter-finals and are "an impressive team".

"(Coach) Vern Cotter has brought them on leaps and bounds, there are some quality players and they are going to cause us a huge threat," said the ex-Cardiff Blues and Racing 92 player.

Centre friends reunited?

Roberts was pleased to rekindle his Wales and Lions centre partnership with Clermont Auvergne's Jonathan Davies, who had been ruled out of the World Cup by a knee injury.

"It was good. He is a quality player," Roberts added.

"But I think as a backline we have got a bit to work on, certainly in phase play.

"A couple of lads have not played for a while and we have got to get things right in training and move up another notch."