Ulster's is generally the most form-driven of the provincial football championships. Most of the counties are within reach of each other if one plays well and the other doesn't, as last week's win for Antrim indicated. Even within such a context, tomorrow's match between Armagh and Tyrone is inscrutably hard to call.

There is a discernible trend in these meetings which favours the underdog. Ten years ago, Tyrone were defending champions and lost narrowly. Six years ago, Armagh were the next hot thing from Ulster after reaching a league final but ended up well beaten by their neighbours.

This time around, it's hard to work out who's ahead on form because neither side had an impressive league. There is probably a leaning towards Armagh because of their experience as a unit and their success last year. The county has also enjoyed a number of ancillary successes this year. Crossmaglen won a third All-Ireland club title while their final opponents, Dublin's Na Fianna, featured two Armagh players, including captain Kieran McGeeney. Queen's, meanwhile, were captained to Sigerson Cup success by Diarmuid Marsden.

Tyrone can point to the capture of another under-21 All-Ireland and the vast experience of their management team, Art McRory and Eugene McKenna. But the mechanics of the team selection haven't been as straightforward. Once again the county team is in need of rebuilding. The intensity of the last five or six years has taken its toll on some still relatively young players, with Fay Devlin, Paul Devlin, Stephen Lawn and Sean McLaughlin all retired although hardly 30. At the other end, this year's under-21s are beginning to arrive.

Nonetheless, there are certain trademark selections. Seamus McCallan was always highly rated as a centre back by McRory and his long injury-imposed exile ends with a recall. Pascal Canavan's vulpine manoeuvres around centrefield have in the past blotted out the influence of Anthony Tohill despite a difference in height of about seven inches. With the McEntees in the Armagh centrefield and given the proclivities of all the half lines, the middle of the pitch will be no place for claustrophobes. The match should come down to whoever can make the most of meagre chances. With Peter Canavan and Marsden at either end, that's not an easy call. Perhaps Canavan's injury will tip the scales. Overall, Tyrone look just a bit too much of a work-in-progress.