GAA ALL-IRELAND SFC Kerry v Tyrone:ON PAPER this is straightforward. Kerry are a better team now than they were three years ago when losing the last decently competitive GAA All-Ireland final; Tyrone, on the other hand, are less impressive than in 2005. Ergo?

On grass, where tomorrow's match will be played, and possibly in the heads of the men who will play it, the issue is not quite as clearcut.

There is too much momentum behind Tyrone and there are too many insecurities about Kerry's progress to the verge of a first three-in-a-row since the champions themselves last accomplished the feat 22 years ago.

It's valid to question how much evidence we really have of Tyrone's revival given the poverty of Dublin in the quarter-final, but Mickey Harte's team fired a good score against Wexford and have unquestionably found a higher gear since wheezing past Mayo in July's qualifiers.

They are vastly experienced, with only two players new to this experience, and it has been seen in the past with Down footballers in 1994 and Offaly hurlers in 1998 that former champions can successfully reinvent themselves despite having done little enough since last winning an All-Ireland.

Tyrone also have the best-drilled system in the game. Every player knows what to do and where to be when in possession and when defending. The level of teamwork is visible in the fast interchange of the attacks and the ease with which other players drop back to cover for team-mates breaking from deep.

Three years ago Tyrone's game had too much pace and intensity for Kerry to stay the distance. That was for partly tactical and partly circumstantial reasons.

As Colm Cooper pointed out last week, Kerry had taken a particularly easy route to the 2005 final, whereas Tyrone's progress made Passchendaele seem like the Leinster hurling championship. As a result there was a major disparity in the readiness of the teams to engage at full throttle.

Kerry struggled for space and had difficulty getting good ball into their forwards despite centrefield superiority, and every misplaced pass was gobbled up and recycled as an attack.

Tomorrow's match is going to hinge on which team can impose their own terms on the game.

A conventional afternoon's catch-and-kick won't be in Tyrone's interest, whereas an amorphous and anarchic scramble won't allow Kerry to play to their strengths.

The main difference between Kerry now and three years ago is Kieran Donaghy.

There have been other improvements but Donaghy, with his quick feet and comfortable handling, has given Kerry an option in the air and in terms of general ball winning they previously lacked.

This season Tommy Walsh has been added and at times has made a sizeable impact.

It was pointed out to me in Kerry that Walsh's and Donaghy's basketball background means they are capable of not only winning ball but also using it in tight spaces. As a combination it marks a huge advance on the ball-winning options of three years ago.

Rumour as far away as Tyrone has speculated that Donaghy's fitness is suspect after the knee injury he picked up at the end of the semi-final.

Although he missed more than a week's training, word in Kerry is the player is fit and showed well in last weekend's practice match. There will still be anxious faces watching his early movements, as it's not fanciful to hold that Donaghy is the central player in the champions' game plan.

If there is a structural difficulty for Kerry it is in the half forwards. Manager Pat O'Shea has tried various options to strengthen the line's ability to compete. One of the most canvassed ideas was to start Paul Galvin on his return from suspension.

One interesting school of thought from within the county is Galvin would be better off starting because he would find it easier to acclimatise at the beginning of the match when everyone is settling in rather than after 30 or 40 minutes when teams will have got to the pitch of the ball and the pace of the match.

But among those who watched training in recent weeks there is a competing view that the captain looks too rusty and off the pace to be started, with the concomitant risk to morale of his having to be substituted after 25 minutes of futile struggle.

As one Kerry realist put it: "Paul Galvin isn't in a box you can take down off the mantelpiece, wind him up and expect him to be as good as he was last September."

The same goes for Stephen O'Neill. He may have been playing club football this summer (although Clann na nGael haven't played a serious fixture in over two months), but like Galvin, he has not played a full intercounty championship match in a year.

On the upside for Kerry, Declan O'Sullivan is more formidable and whoever marks him will take a risk if he spends as much time as Conor Gormley did three years ago protecting the full backs.

In Galvin's absence, for however long, the half forwards will have to compete better than in previous matches and also provide a better platform for the inside line.

The half backs will also need to be more disciplined in holding the line because if they become disconnected, the likes of the rejuvenated Brian Dooher, wing backs Davy Harte and Philip Jordan and the team's best player this season, Enda McGinley, will pour through.

It is vital for Tyrone that Seán Cavanagh is free to play full forward, as being forced to bring him back to sort out centrefield (where Darragh Ó Sé and Séamus Scanlon will be harder for Collie Holmes to disrupt than were Dublin) will be a bad sign for Tyrone.

Neither Tom O'Sullivan nor Marc Ó Sé may have the strength to cope with Cavanagh on full rampage but O'Sullivan is big and fast enough, and it was not for nothing that Ó Sé was named Footballer of the Year 12 months ago. So the likelihood of Tyrone getting free passage along the endline is small.

Ultimately Mickey Harte's team will squeeze Kerry, and if the champions crack, their title is gone. But even a supply of ball similar to what they got in 2005 will be more lethally used by Kerry, and that is where Tyrone are short of answers.