For much of the championship Mayo and Dublin have progressed routinely and any exhilaration has been tempered by the knowledge that in these games of Russian roulette none of the chambers were loaded.

That changes tomorrow in Croke Park.

Both of these counties return to the penultimate stage of the All-Ireland burdened by about as heavy a cargo of regrets about the previous year’s championship as has ever been carried by semi-finalists.

Mayo have attracted great commendation for the drive and ambition they’ve brought to the latest year of their crusade for an All-Ireland, as well as the subtle but perceptible changes they’ve made to tactics and personnel.

It’s not hard to state a case for the Connacht champions. They have a range of centrefield options that is superior to Dublin’s and have refashioned the attack by using Aidan O’Shea as a marauding full forward, using his strength and fielding ability to great effect – he has five goals spread over their matches to date, even if Galway’s own goal wasn’t directly credited to him.

Claiming the honour

There is the buzz of new management, the Pat Holmes and Noel Connelly combination that led six of today’s starters to All-Ireland under-21 success, as well as the piston-drive of four years of coming agonisingly close but not quite claiming the honour of bridging the 64-year divide back to Mayo’s last All-Ireland.

O’Shea’s switch is one of the differences from recent years. So too is the rediscovery of Tom Parsons in a dynamic centrefield role and to an extent Diarmuid O’Connor, whose rookie season last year was confined to Connacht – he’s an industrious and talented footballer at wing forward.

They have also had a more testing run if only for their harder quarter-final, against last year’s All-Ireland finalists Donegal, but they won so comprehensively that as a diagnostic exercise – whatever about its morale-boosting properties – it didn’t really do what it said on the box.

Anyway, experienced teams – sixth and fifth successive semi-finals respectively – don’t need to be brought up to speed that desperately, although the lack of competitive fixtures is not ideal.

Dublin’s lengthy and uncomplicated run to this point hasn’t made any serious demands on their mental strength and tomorrow’s match is going to come like a shot of pure adrenalin.

Dublin also have less proving to do at this level. Two All-Ireland titles in the past four years means that most of the team have proved themselves in the most tangible way.

It’s ironic that after spending so much time mastering the tactical intricacies of setting up against blanket defences, Dublin find themselves among the last three standing in the championship along with two teams who don’t play that system.

Still, an improved defensive sensibility is no harm for a team that has conceded three goals in each of its two most recent All-Ireland semi-finals.

Legitimate questions

Whereas there are legitimate questions about how tight marking Dublin’s corner backs are given that neither Johnny Cooper nor Philip McMahon are specialists, Rory O’Carroll is a formidable full back and the switch of Cian O’Sullivan to centre back has greatly improved the unit given his pace – in a turbo-charged line with James McCarthy and Jack McCaffrey – and defensive instincts, which will surely see him monitoring O’Shea’s activity on the edge of the square.

So far the only goals conceded by Dublin have been the two against Fermanagh, both in unusual circumstances.

Stephen Cluxton’s kick-outs will be subject to the usual scrutiny but despite that intense focus, Dublin have been known to win matches even when the opposition crack the code, as in the 2011 All-Ireland final.

They also have plenty of mobility around the area but the ability of Séamus O’Shea, Parsons and Moran in the air does give David Clarke a feasible choice of going straight to the middle with his restarts.

There is also improvement up front, even if the absence of Eoghan O’Gara removes a useful plan B; after all, his arrival turned the tide in the All-Ireland final two years ago.

Dean Rock’s accuracy from placed balls saves Cluxton all the commuting and puts a hefty price tag on fouling.

Ciarán Kilkenny’s return from injury has been another factor in the team’s progress. His workrate and ability to shoot points have eased the difficulties Paul Flynn has been having in hitting top gear.

It could go either way but it’s easier to follow the directions that lead to Dublin.