Lack of common experience makes tomorrow's Bank of Ireland All-Ireland football semi-final at Croke Park particularly hard to call. Kerry's forwards have dazzled the public at various stages this year but they haven't encountered such claustrophobic opposition. Armagh's ability to grind down opponents and strike for crucial scores has been impressive but they haven't met a six-gun attack like Kerry's.

Defences will hold the key and the team which most successfully copes with its shortcomings at the back will advance. Kerry's one big match of the year was against defending Munster champions Cork. In the first half, their forwards put on an exhibition and the team racked up an 11-point lead.

After the break, however, Kerry disintegrated and were nearly caught. Whereas the pressure came on in Killian Burns's corner as Colin Corkery helped himself, the problem originated at centrefield where Dara O Se and Donal Daly lost the initiative and the half backs were swamped.

It was the most vivid illustration of why playing Seamus Moynihan at full back is fraught with danger. Had he not been inside, Cork wouldn't have cleaned up on the breaks to the extent that they did. Tomorrow's opponents, especially the Kieran McGeeneyled half-back line, are even snappier on the break and unless centrefield gets a grip, the Munster champions will be in big trouble.

Balancing the scales is Armagh's difficulty at full back. Much was made of Ger Reid's sterling performance in the Ulster final, yet a below-par Enda Muldoon broke even. Furthermore, the covering across by the McNultys meant that Johnny McBride ended up with space and 1-3. There'll be no covering across with the Kerry forwards to watch and so Reid will have to be more in charge of Dara O Cinneide.

In the first half against Cork, O Cinneide was in great fettle and the two penalties he converted were symptomatic of a confident player. Reid will need all his doggedness and robust mentality to limit damage if the ball starts to run for Kerry.

Centrefield will be important tomorrow, not in the high-fielding, contest-of-athleticism sense but territorially. Armagh will crowd from the area to try and stifle any decent supply into the Kerry forwards. They will also seek to isolate their forwards in space and hope that it works out more successfully than last year.

There are a couple of reasons to believe it will. For a start Oisin McConville was playing in last year's semi-final in terrible personal circumstances, with his father extremely ill. Secondly, Stephen McDonnell is a decent addition to the team, contributing pace and accuracy in attack.

Thirdly, the McEntee twins have adjusted to the demands of intercounty football.

In addition to his athleticism, John McEntee has one of the coolest nerves in the game and can kick important scores or pick out the right ball with two opponents hanging out of him.

Another important difference between this and last year is that Kerry, for all their forward talent, don't have a playmaker like Trevor Giles available and, as he proved last year, in the thickets of an overcrowded field, the ability to pump in accurate ball is priceless.

Armagh's principal failing is their mentality. Whether from an excess of caution or a paralysing fear of losing, the team has a tendency to fall back on even unexceptional leads and try to shut out opponents for long periods. This backfired against Meath last year and very nearly against Derry this season. To do it tomorrow would be dangerous, because the Kerry forwards are comfortable picking their shots from anywhere within 35 metres.

The sides are well matched, down to each having a star performer on the bench in Diarmuid Marsden and Maurice Fitzgerald. Kerry's best looked better than Armagh's but the second half against Cork was worse than anything the Ulster champions have perpetrated. Armagh's matches have been grimly competitive whereas Kerry's have been grimly uncompetitive.

Even the Cork match consisted of two uncompetitive halves making a competitive whole. The view here is that Armagh's experience has been more relevant.