All-Ireland SF semi-final Dublin v Armagh Croke Park, tomorrow, 3.30 Live on Network 2: Tomorrow the Bank of Ireland All-Ireland football championship will - barring a replay - resolve itself into a straight, two-way contest between Kerry and either Dublin or Armagh. Seán Moran reports.

After the disappointment of last week's depressing first semi-final, the football world could do with something more edifying and competitive.

Everything is well set for expectations to be met. The stage is there with a packed Croke Park - and even an historic support bill provided by the Longford minors - and probably more of the fine weather that the GAA appear to have contracted for with the powers above during this otherwise disappointing summer.

On the field there is the intriguing prospect of a clash of opposites with enough in common to make it a desperately hard match to call.

With a memorable summer turning to autumn many footballing people around Dublin can't remember a time when the county team's exploits generated such frenzy around the city. The colour, the flags, the hordes of replica jerseys, the acknowledgement by Arnotts during the week that their sponsorship of the county team was a factor in their rising profits, all bear witness to the way in which Dublin has responded to its new team.

Of course, this is precisely what a team like Armagh can engage with and exploit. The sight of the capital high on its own prospects has been the motive influence behind many a famous victory and in this case the Ulster champions are well-primed.

Beside the perennial urban-rural divide there is another contrast between the teams. Dublin are a new team, recruited and deployed by the new management of Tommy Lyons and his selectors. From downbeat beginnings nearly three months ago the side has developed, expanding its portfolio of victims and developing its own potential.

Each step of the championship way has brought new challenges and raised new question marks over the team's ability and character. By and large those rising standards have been met and exceeded. Tomorrow is a further stage of that process.

It is a dangerous stage because of who Armagh are. A voice close to the team said this week that the match had all the appearances of a banana skin. Even in this sensible foreboding was an illustration of the subconscious threat.

A banana skin is an unexpected and avoidable pitfall. Armagh aren't a banana skin. The northerners have a better cv at this level than their opponents, bags of experience, like Dublin the dynamic of new management and a knowledge from Crossmaglen's club exploits of what it takes to win big.

The laboured advance past Sligo shouldn't be viewed as much more than further evidence of the Connacht side's developing competitiveness at the highest level. After all they dumped a Tyrone side seen by many as All-Ireland material.

The county's poor track record in recent semi-finals and Croke Park outings shouldn't be exaggerated either. If 1999 was disappointing it was because Armagh had Meath dead in the water but failed to make it count. A year on and they were agonisingly short over two matches and extra time against the eventual All-Ireland champions Kerry.

Where they were forced to blink two years ago is a zone beyond anything Dublin have so far experienced.

There are also similarities between the teams. Both have goal scoring potential in attack and play to exploit their inside forwards. Both have potential but inconsistency at centrefield and both have vulnerabilities in defence, which must be a tempting prospect for either of them.

We don't know how Dublin will line out except that it won't be as selected. Shane Ryan is fancied to move to centre forward on Kieran McGeeney. This switch makes superficial sense in that the recalled Dubliner is strong and willing. But trying to out-muscle McGeeney isn't a tactic on which any team would want to be depending too much.

It is possible that the totemic Armagh centre back could be tested more imaginatively by the guile of his Na Fianna clubmate Dessie Farrell.

For all Dublin's exquisitely timed goals, too, disproportionate a number have been coming from Ray Cosgrove. His finishing has been sensational. Put him in on goal and he scores. But there's nothing surer than that Armagh will stifle and harass the Dublin full forward, packing the defence to eliminate the possibility of his creating space for goal chances.

This would, indeed, be welcome room for manoeuvre for the other forwards but apart from Alan Brogan's beauty against Kildare, none of the others have demonstrated much goal threat. Armagh are better served. Steven McDonnell has been doing it longer than Cosgrove, Ronan Clarke has been on target and Oisín McConville is due to get in on the act this season.

Centrefield will have a major bearing on the outcome. It's slightly loaded in Dublin's favour. Will Ciarán Whelan's tour de force the last day prove an aberration or a platform for world domination? Paul McGrane is capable of coping with the Dubliner but one source in the county expressed the opinion that Armagh will need more than a 50-50 shakeout to make sure of winning.

Because of Whelan's scoring capacity Dublin possession is more dangerous and in Darren Magee the Leinster champions have the more likely junior partner. Magee's workrate and catching ability were impressive the last day and John Toal will need to apply himself more consistently to defuse the threat.

Both teams will work hard throughout the field. Dublin's forwards went a long way to beating Donegal by shutting down their leisurely build-up from the back. Armagh are another team that don't go long when clearing the lines and may be under pressure as a result. Armagh will present similar problems for Dublin, with Diarmuid Marsden rated by one respected source in the county as the team's best tackler, and off whose defensive interventions scores have come.

Where does that leave the likely outcome? In the middle of all the evenly balanced considerations two stick out as possible swing factors for Dublin. Firstly, the team has more pace around the field, giving it the potential to punch occasional holes in even the tightest cover. Secondly, Dublin have momentum. They have improved at each stage, finding a little more within themselves as they go. Perhaps they can find the wherewithal to surmount one more formidable barrier.