by Brendan Cole

Ireland and Wales will face-off on Saturday to decide the 2009 RBS 6 Nations. Who has the edge in the head to head battles?

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15. Rob Kearney v Lee Byrne

Rob KearneyKearney has been having an excellent Championship but threw in a few nervy slips against Scotland – including the loose kick that almost ended with a try before half-time. His ability to shift the momentum from the full-back position is potentially key. For Wales, Byrne has kicked exceptionally well, finding huge length on a consistent basis, and has hit the line nicely in attack, most notably for a try against France. Front on tackling is sometimes a weakness.

Verdict: Kearney is more robust and safer in the tackle, and is equal to Byrne’s kicking game, but Byrne’s ability to time his interventions into the line is a potential plus point for Wales. Two top players and it may depend on the shape of the game as to which one’s skills end up making the biggest difference.

14/11. Tommy Bowe v Mark Jones

Tommy BoweBowe has made several excellent carries down the wing during this tournament, defying the doubters by using his combined strength and speed to give tacklers a host of problems and lift the pressure on his team. Jones, who took over from the injured Leigh Halfpenny mid-way through the tournament, has looked less of an attacking threat and also seems unsure of himself in defence at times.

Verdict: Jones can do the basics but otherwise adds little to the Welsh attacking play; Bowe’s physique and pace is a problem for any defence. Advantage Ireland.

13. Brian O’Driscoll v Tom Shanklin

Brian O'DriscollO’Driscoll has oodles of class – exceptional vision, touch, acceleration and timing – but Shanklin’s strength, determination and footballing intelligence go a long way towards making up for a lack of the same natural gifts. Shanklin is good enough to cause Ireland severe problems if not managed properly, but the quicksilver O’Driscoll has the ability to make huge plays on the big stage may just have more to say in this one.

Verdict: O’Driscoll is without equal but Shanklin can do enough over 80 minutes to make sure Wales are not totally eclipsed. Advantage Ireland, but not by much.

12. Gordon D’Arcy v Gavin Henson

Gavin HensonHenson is retained in the Welsh first XV despite several discipline breaches that other coaches might well have punished because Warren Gatland sees his ability to link the Welsh half-backs to the back three as essential. Could the failure to discipline Henson have an impact on team spirit? D’Arcy has taken over from Paddy Wallace on the basis of his ability to pierce the Welsh defensive line and get Ireland going forward, both of which he can accomplish against this Welsh defence. Passing is not his greatest strength but Ireland will most likely play a narrow game so it may not count against him too much.

Verdict: Henson’s attributes are obvious – passing and power - but he is immature and can have a bad impact on the team if having an off day, while D’Arcy’s ability to cross the gainline is a key for Ireland. The Welshman has more variation though, and it could just be advantage Wales.

11/14. Luke Fitzgerald v Shane Williams

Luke FitzgeraldFitzgerald has been excellent throughout in this tournament, showing the expected attacking flair but also superb game reading and execution in defence. Williams has a brilliant step and also the chutzpah to try things from anywhere – a major threat if he gets moving. He is a major turnover risk when tackled though.

Verdict: Ireland’s scramble defence is much sharper now than 12 months ago and could limit Williams but he is a huge scoring threat to any side. Even though Fitzgerald has made dozens of quality plays so far in this tournament, the Welshman's record speaks for itself and he can make game winning plays. Very tight between them, with Fitzgerald having a better all round game but Williams having a slight edge in X-Factor.

10. Ronan O’Gara v Stephen Jones

Ronan O'GaraBoth of these Lions contenders come into this match under something of a cloud. Partly, that is because out-half has probably been the toughest position to play in this tournament due to the combined effect of rules changes and improved defence from all teams. Aside from struggling to launch attacking play at times, O’Gara and Jones can have wobbly kicking outings and have done so already in this tournament. The forward battle will play a role in deciding which gets the space to operate in but that cuts both ways and if either out-half can kick well enough to get his pack on the front foot early, it could prove decisive.

Verdict: O’Gara has a better range of kicks in his arsenal and can make his backline dangerous when running onto the ball – his game reading and eye for a chance are also superb. His form is variable at best, however. Jones is a stronger tackler and runner with ball in hand. Hard to call, but it could be advantage Ireland with O’Gara due a big game.

9. Tomás O’Leary v Mike Phillips

Tomás O'LearyTwo excellent athletes experiencing criticism for providing mediocre service this tournament. The special skills have not come through so far with Phillips not finding the same gaps this season as last with the ruck area far tighter and O’Leary’s superb cover tackling yet to be called on. Ireland may yet end up being glad of the insurance policy he brings to the table.

Verdict: O’Leary must tighten up the accuracy of his basics and must also show improved decision making. If the match opens out, it could be advantage Wales.

1/3. Marcus Horan/Adam Jones

Ireland’s scrum wobbled against Scotland last week but it is in theMarcus Horan match after those types of days that Hayes and Horan really tend to produce. Horan is well used to Adam Jones at this stage and should handle him readily enough.

Verdict: Horan’s contributions around the park have been excellent to date - he is putting the head down and using his power to better effect than ever before - and he has the edge in this one.

2. Jerry Flannery/Matthew Rees

Jerry FlanneryRees has been quiet enough and can possibly be got at in the lineout – video analysis will play a key role. Flannery has been typically busy – overbusy some might say, in that he can take on ball better left to bigger men at times – but the Irish lineout should be guaranteed as his delivery has been exceptional.

Verdict: Advantage Ireland, particularly once Flannery can maintain a certain level of poise in his play round the park.

3/1: John Hayes/Gethin Jenkins

Hayes also had a torrid time last week and saw at least two key John Hayespenalties given directly against him. It will be a surprise if he is not right on the ball this time around and with much of Ireland’s lineout and maul (a minor factor, but still important) resting on his shoulders, he could prove a match-winner. Jenkins is a formidable opponent, and though he is unlikely to make a killing in the scrum, he can contribute to telling effect around the field.

Verdict: Hayes has a big one in him, but Jenkins’ work-rate is the best of any prop in this tournament. Advantage Wales.

4. Donncha O’Callaghan v Ian Gough

Donncha O'CallaghanBoth work-horses who play alongside more celebrated partners. O’Callaghan had his best game so far against Scotland last week and though he is probably the slower of this pair his sheer determination and ‘dog’ in the tight makes him a difficult opponent for any side. Gough’s tackle on Nick Easter against England epitomised the level of mental commitment he brings to the table for Wales and he adds plenty to their high intensity rucking and tackling games.

Verdict: Two tough men but Gough’s speed and open field contributions may just put him ahead.

5. Paul O’Connell v Alun-Wyn Jones

O’Connell has worked phenomenally hard this tournament, Paul O'Connellepitomising the Martin Johnson second row style by simply running himself into the ground for 80 minutes. His lineout play – and calling – have also been supreme. Wyn-Jones has better hands and athleticism, but may not match O’Connell’s immense work-rate.

Verdict: Jones looks good and can make plays, but O’Connell’s hard edge and ability to keep giving for phase after phase put him ahead.

6. Stephen Ferris v Ryan Jones

Stephen FerrisJones has not gotten into this tournament with an anonymous match against England, a poor outing against France and a bench berth for most of the Italy game amounting to his contribution to date. In contrast, Ferris has been making hay – establishing himself as the best six in this tournament by a margin going into this one. The Ulsterman’s ball carrying and tackling have kept Ireland going when things get tough more than once.

Verdict: Jones badly needs to recover his form and even if he does get back to his best, Ferris looks a cut above.

7. David Wallace v Martyn Williams

Wallace has had difficult spells – the opening half hour against David WallaceScotland being the most recent – but has come through in a big way when needed. His ability to beat tacklers with footwork and/or power through them will be a huge test for the Welsh defence; are Ireland due one of those iconic 40 yard breaks down the field? Williams has not had things go his way with Wales struggling to connect out-wide and the new breakdown laws have nullified some of his strengths. If the game is tight, he is still a very canny operator, but lacks the ball carrying power the Irish back-rowers can deliver, and this tournament’s big matches have so far been decided by strength in that department.

Verdict: Wallace is not quite as good a link-man but the way this tournament has gone his ability to dominate the collisions gives Ireland the edge.

8. Jamie Heaslip v Andy Powell

Heaslip eventually reacted well to being dropped against Jamie HeaslipScotland, making a couple of key carries and scoring a very good try. Powell is turning into a bit of a curate’s egg of a player. Clearly a powerful physical specimen and possessed of some ball skills, he has mastered the knack of attempting tough plays that add little to his team’s cause. Is he turning into a bit of a Sebastian Chabal figure?

Verdict: Heaslip’s speed and ability to make big, forward looking plays makes him a potential game-breaker for Ireland. Powell looks more like a potential target for Ireland.

Coach: Declan Kidney v Warren Gatland

Declan KidneyGatland won the mental game ahead of this fixture last year but has found himself punching air with his efforts to get at Ireland ahead of this one. If the key to the pre-match banter is making the other fellow look a little foolish, Kidney is ahead. Tactically, Kidney’s conservative, ball-carrying and forward based style also looks to be more suited to the shape of this year’s tournament.

Verdict: Two great coaches but with Gatland still searching for a game that works, and flailing around a bit in the ‘mind-game’ battle, Ireland – playing winning rugby based on their superb back-row’s ball carrying - just have the edge.

Bench: Wales v Ireland

Peter StringerIreland have a very solid option at hooker in Rory Best and the potential to change their in the backs through Peter Stringer and Padd Wallace.

There are question marks over some of the forwards though. Denis Leamy had a disappointing half hour against Scotland before getting injured and Mick O'Driscoll and Tom Court are not players of the calibre of the men they might end up replacing.

Wales also have problems. Their depth has been sorely tested, nowhere moreso than at scrum-half, where they must rely on London Irish sub Warren Fury. The forward replacements are also not particularly intimidating, especially after last week's poor outing against Italy. Jamie Roberts and James Hook are obvious potential danger men however.

Verdict: Stringer could prove a key man for Ireland while Best also has the capacity to have a very positive impact. However, the quality of Hook and Roberts, both of whom might easily have started, possibly gives Wales an edge.