By Sarah Mockford, Rugby World Features Editor

WALES v IRELAND

Saturday 12 March, 5pm, Millennium Stadium, Referee: Jonathan Kaplan (SA), Live on BBC1

Both teams have played three and won two in this year’s RBS 6 Nations. Both teams have won a Grand Slam in the past three years. Both teams have an ongoing debate about who is their best fly-half. But who is going to win tomorrow’s game between Wales and Ireland? Well, here are some pointers about some of the battles set to take place in Cardiff…

THE PENALTY COUNT

Much has been made about the number of penalties Ireland have given away so far in this championship – in fact, Warren Gatland is going to talk to the referee about it before the game after no Irishman was sent to the sin-bin in Scotland despite repeat offensives at the breakdown – but it’s Wales who have conceded more penalties in the three games to date, 36 to Ireland’s 34. Both sides will need to significantly reduce their infringements, particularly in their own half which has been a trait of Ireland’s this year, or they will be punished by the boots of the opposition kicker.

THE BACK ROW

Ryan Jones is back to something like his best form at No 8 for Wales and will be keen to maintain that level of performance as he wins his 50th cap. He seems to be enjoying his role as the senior statesman in the back row alongside young guns Sam Warburton and Dan Lydiate, who have both impressed with their work-rate and get better with every game. They will face a stern test from the hard-running Irish trio, who are all strong ball-carriers. However, Sean O’Brien does have a tendency to lose the ball in contact and Warburton could make his presence felt at the breakdown more than his opponents.

THE FLY-HALVES

Ireland have opted for the consistency and territorial kicking game of Ronan O’Gara while Wales have gone for the flair of James Hook, so it’s a real contrast of styles.

Risky business: James Hook

Mr Conservative: Ronan O'Gara

Hook was undoubtedly a key man against Scotland but Gordon D’Arcy and Brian O’Driscoll will target him mercilessly in Cardiff to see if he flounders – can he still work his magic under intense pressure? Can he control the game and clear the danger with a kick as well as exploiting space? These are questions he must answer in the positive if Wales are to have a chance, otherwise O’Gara will be given the possession he needs to keep Wales pinned deep in their own half.

THE BACK THREE

Both teams have dangerous runners who given time and space can counter-attack with the best of them. Lee Byrne is rediscovering his best form for Wales and with Leigh Halfpenny back in the side and Shane Williams on the other wing, Wales could cause Ireland lots of problems if they put in poor kicks. The two wingers can dart through the tiniest of gaps to create scoring chances and will be looking to do so here. Ireland’s back three is strong too and Tommy Bowe will want to get one over his Ospreys team-mates, while Luke Fitzgerald is settling into the full-back role and Keith Earls has plenty of gas – but they will need to perform better than they did in this challenge.

WALES: Lee Byrne; Leigh Halfpenny, Jamie Roberts, Jonathan Davies, Shane Williams; James Hook, Mike Phillips; Paul James, Matthew Rees (capt), Craig Mitchell, Bradley Davies, Alun Wyn Jones, Dan Lydiate, Sam Warburton, Ryan Jones.

Replacements: Richard Hibbard, John Yapp, Jonathan Thomas, Rob McCusker, Dwayne Peel, Stephen Jones, Morgan Stoddart

IRELAND: Luke Fitzgerald; Tommy Bowe, Brian O’Driscoll (capt), Gordon D’Arcy, Keith Earls; Ronan O’Gara, Eoin Reddan; Cian Healy, Rory Best, Mike Ross, Donncha O’Callaghan, Paul O’Connell, Sean O’Brien, David Wallace, Jamie Heaslip.
Replacements: Sean Cronin, Tom Court, Leo Cullen, Denis Leamy, Peter Stringer, Jonathan Sexton, Paddy Wallace.