Kerry v Tyrone: Kerry are unique among the four teams left in this All-Ireland race. Their style of play of moving the ball quickly through the field to their inside forwards has been tried and trusted down the years and has yielded the results, writes John O'Mahony.

Dara Ó Cinnéide, Colm Cooper, Mike Frank Russell, Johnny Crowley and this year's new kid on the block, Declan O'Sullivan, have all benefited from this positive attacking style. Against Roscommon in the quarter-final it seemed they could score any time they put the foot on the accelerator.

The other teams in the semi-finals have developed a contrasting game plans in their search for success. It was perfected by Armagh in last year's All-Ireland success: crowding up to 12 and 13 players behind the ball when the opposition is on the attack and then breaking quickly out of defence on a counter-attack.

This gives them space in their forward line because all of the players have been sucked back to the other end of the field.

Tyrone have now developed this style to an even greater degree. In the quarter-final against Fermanagh, on a few occasions I noticed only one Tyrone player, usually Peter Canavan or Owen Mulligan, inside the opposition half.

Donegal also adopted the same tactics in their two matches against Galway with ultimate success. The message is simple in the modern game: the massed defence is the winning formula and is being executed with clinical efficiency.

So the task for Kerry tomorrow is twofold. Firstly, they have to break down the crowded Tyrone defence if they are going to have a chance of celebrating their 100th anniversary of their first All-Ireland title in 1903, and, secondly, they have to cope with the substantial scoring threat provided by the Ulster champions in the form of Canavan, Mulligan, Gerard Cavlan and company.

It has been suggested in some quarters this week that Sunday's result hinges on the tussle between Canavan and Séamus Moynihan. I don't agree. The scoring threat in the Tyrone forwards is not all on Canavan's shoulders nowadays, and anyway it is by no means certain Moynihan will be the player to mark him.

Both defences have some question marks over them, with Kerry worried over their late concession of three goals against Roscommon and Tyrone having problems in their full-back line through most of the Ulster championship.

I doubt, however, if Kerry would have been so porous in the quarter-final if the game had been closer. They haven't got the tightest defence in the country, but they have a number of solid defenders like Mike McCarthy and Tomás Ó Sé.

For the Ulster champions, Cormac McAnnallen seems to have made the transition into a top-class full back, although he faces his toughest challenge yet against a potent Kerry full forward line.

Midfield is always a key area and tomorrow is no different. Tyrone, with Kevin Hughes and Seán Cavanagh in great form, seem at last to have solved their problems in this area.

Cavanagh in particular is having an outstanding season, and considering he is still under-21 it is incredible to see his all-round ability in ball-winning, mobility, and scoring.

He has not only provided an answer in the middle of the field, but in doing so has released McAnnallen to solve the full back position.

For Kerry, Darragh Ó Sé will have gained a lot of match fitness since the quarter-final now that he has shaken of his ankle injury.

Eoin Brosnan, who struggled somewhat at centre forward for the last couple of seasons, is the latest partner for Ó Sé and his contribution will have a vital bearing on the outcome in this area.

To call a winner in this semi-final is very difficult. It is a defining game for both teams. Kerry need to deliver after the fiasco of 2001 and the second-half fade-out against Armagh last year. The prize for them for winning is the chance to establish themselves as the best team over the last 10 years, as well as to celebrate their first All-Ireland win 100 years ago.

For Tyrone it is the chance to deliver on all the promises of recent years and join their neighbours Armagh in the Promised Land. My hunch is that Tyrone will have to wait at least another year.

In an interview with Seán Moran.