CIRCUMSTANCES can certainly force the best-laid plans to be altered. Circumstances, rather than the desire for major alteration, was the major factor at play for Ireland's selectors in constructing the team to meet Scotland at Murrayfield this afternoon, when Ireland's involvement in the International Championship this season will come to an end.

Both countries go into the match in the immediate aftermath of very comprehensive defeats to England. Bearing that in mind, neither side could be said to have a psychological advantage.

Ireland field a team that includes five changes in personnel - and a positional switch - from the side beaten by England.

Four of those were enforced by injuries. It is not unreasonable to suggest that had the selectors not been restricted in their choice through the absence of Eric Elwood, James Topping, Nick Popplewell and Eric Miller, then instead of having to alter one third of the team, the more likely scenario was that Topping, alone of that quartet, would not have survived.

The one unenforced change that has been made is at scrum half, where Brian O'Meara comes in for Niall Hogan, who had such a difficult afternoon against England.

The Scots have made just two changes to the side that lost so comprehensively to England and both are in the back line, which is also amended with two positional alterations.

As anticipated, former rugby-league player Alan Tail has been recalled to the international arena of rugby union after nine years and plays at outside centre. He will be partnered by Gregor Townsend, who is moved from outhalf. That berth goes to Craig, Chalmers and Tony Stanger moves from centre to wing.

The men to lose out are Derek Stark and Ronnie Eriksson in the reshuffled backline. The only change in the pack is a positional change that sees Rob Wainwright switch berths in the back row with Peter Walton.

Bearing in mind the manner and nature of Scotland's defeat by England, the fact that there are so few alterations may illustrate a belief that the team will play infinitely better than they did against England. Wales also defeated the Scots by a record margin.

It may also suggest that the talent is not available, certainly in the pack, to make effective chances. The Scottish clear-out, after they conceded that record 34 points to the Welsh, certainly did not bring the necessary level of improvement against England who won 41-13.

Scotland coach Richie Dixon said of the many changes made over the three matches: "We are putting ourselves under pressure to come up with a team and style of play which will produce consistent results".

The backline that the Scots are now fielding is a very good-looking attacking unit, if not well endowed defensively. Also, if they have limited options in the pack, they do have options behind the scrum - and have exercised them.

That Scotland backline is infinitely more experienced than the Ireland line up, containing as it does: Stanger; Townsend; Tait; Kenny Logan; Chalmers and Bryan Redpath. Well over loo caps in that sextet - and still - counting.

In contrast, Ireland field a backline that includes two under-21 players, Denis Hickie and Brian O'Meara, who have three caps between them, and Kurt McQuilkin and David Humphreys, who are both in their second year in international rugby and neither of whom were chosen in the side in this year's championship until now. Jim Staples, Maurice Field and Jonathan Bell represent the experience and the only Irish backs to have" played in Murrayfield in the past are Staples, and Bell.

With Nick Popplewell gone, the element of experience is certainly missing from the front row. It is now made up of two players with three caps between them, Paul Flavin and Ross Nesdale, and Paul Wallace is in his second year in the championship. There is more experience in the back five - and Ireland will need it.

In view of Ireland's poor record at Murrayfield over the last decade - they last won there 12 years ago - maybe it is as well that so few of the Ireland players have played there before. They will not be inhibited by past events at the ground.

Ireland coach Brian Ashton, now installed on a permanent basis which should certainly help the Irish players, will have handed out the lessons, if not the admonishments, about elements of the performance against England.

Foremost in that respect was the folly of trying to attack from near their own line without the necessary level of support on hand to make it pay.

The Scots, noted scavengers who live off the mistakes of the opposition rather than their own creative skills, will punish Ireland and have the backs to do it if the possession is surrendered in any area of the field. Ireland also paid a high price for the concession of needless penalties and that lack of discipline is something Ireland can ill afford.

The Scots look to have the better attacking backline and in Redpath and Chalmers, a halfback pairing that is experienced, accomplished and endowed with the talent to make the best use of those outside them. Tait's only previous appearance against Ireland was in 1988 at Lansdowne Road, the last occasion Ireland defeated Scotland. He is the only survivor on the field today from that match.

While Popplewell's experience and scrummaging ability represents a loss to Ireland, as does Miller's absence, the Irish pack looks well capable of not just matching, but beating the Scots.

Jeremy Davidson has been a key man, not only in the line out, but in other aspects of forward play. He and Paddy Johns have formed a strong second-row pairing that should ensure good line-out possession, and the return of Ben Cronin at number eight gives Ireland a line-out option at the back. But the level of Cronin's industry and defensive reading will need to improve under them. Their facility for living on the fringe and indeed beyond it, has long been a notable and, at times, effective part of their game.

Today Ireland must drive them back and use the maul with purpose and effect. The back row of David Corkery, Cronin and Denis McBride have a key role to play in support and defensively. They will need to offer a tight screen against the breaking powers of Redpath,

The Scots, who traditionally like to ruck rather than maul, have not greeted the new laws with much enthusiasm, nor prospered and Chalmers and the marauding type of game that is so much a part of Scottish back-row play.

Ireland's young half-back pairing of Humphreys and O'Meara has very distinct possibilities. But they must get the service and O'Meara the protection necessary. He is a quick and accurate passer of the ball and that will give Humphreys more time to exercise the right options.

The midfield of Field and McQuilkin looks solid in defence and will need to be. Field has played very well for Ireland this season and McQuilkin, while not endowed with great pace, is a perceptive footballer. Hickie and Bell have the pace to capitalise on opportunity and Staples is good coming into the line.

If the Irish pack can reproduce the form revealed against Wales, play with the same dedication of purpose and maul and ruck as they did that afternoon, then they will get the better of this Scottish pack.

The Scottish back five of Doddie Weir, Andy Reed, Wainwright, Walton and Ian Smith is far more experienced than the front three, but Ireland must dictate the pattern up front to win this match.

The Scots will go for the quick score and too often in recent years, have got it against Ireland. Two years ago, it was Ireland who struck the early blows and then allowed Scotland back into the match to dictate the second half.

If the Irish pack gets on top and O'Meara and Humphreys strike the right accord at half back - Humphreys' kicking must be well- placed and make Scotland full back Rowan Shepherd chase and kick the ball back to touch - then Ireland can win it. But Ireland must create and take opportunities.

The place kicking will be very important. Two years ago, Gavin Hastings' kicking was crucial in Scotland's 26-13 win - he landed six kicks from six attempts.

A win for Ireland would give a 50 per cent return from the championship. The side has the capacity to achieve it, it must also have the will. It is time that the Murrayfield bogey was laid to rest as the Cardiff bogey was, so effectively, in 1985 - coincidentally - the last occasion Ireland won at Murrayfield they won their other away match in the championship.