This magnetic rivalry has become a guessing game. Weigh both teams up collectively or pound for pound and the scales are just about even. It must have been a busy six days in both camps. Who has learned more?
For Mayo, the areas in need of patchwork after Sunday's pulsating draw were obvious. They didn't crumble under the force of Kerry's pressure on their kick-out but they faltered at critical times and need to find more obvious outlets for David Clarke. At the other end, they need to stop banging cheap wides.
Limiting Kieran Donaghy remains the big – if not the only – issue. It is almost impossible to entirely marginalise the Stacks full forward and Mayo failed to do this a week ago. But Donaghy didn't cause the sky to collapse around Mayo ambitions in the way he has done in previous summers. The Aidan O'Shea-as-policeman tactic, for all the criticism, did manage to stave off a cataclysmic outcome: a high ball, an early goal, the Kerry forward line purring and everything going south.
If manager Stephen Rochford leaves O'Shea to mark Donaghy again, then the obvious temptation for Kerry will be to have Donaghy again leave the square and try and make mischief elsewhere. But even though Donaghy's creative instincts were alive and well around the borders of the attack a week ago, it is difficult to gauge what Kerry's attack lost through his positional displacement.
James O'Donoghue had a frustrating afternoon and although Paul Geaney hit 0-3 from play, he was relatively well-contained. The fun will start if Kerry start bombing high ball at Donaghy regardless of whether O'Shea is there or not.
Bad habit
If Mayo had managed to curtail their bad habit of gifting Kerry with untidy frees from scoring positions, then the Kingdom attack would have struggled to keep the board ticking over.
With Michael Geaney absent through injury, the fitness of his replacement Donnchadh Walsh becomes a more pressing issue for Kerry. Put simply, the Kingdom have nobody else to replace what he does: constant motion, terrific at moving the ball on; always open as option and brilliantly fly at ghosting through defences to land an occasional big score or two.
There are other decisions, too, for the Kerry management. Dare they go out again without giving some sort of protection to their full-back line? If so, then the pressing high defence which Éamonn Fitzmaurice’s teams excel at needs to play with more intent. It would be a surprise if that unit permits Mayo’s rearguard to thread through the supply of sympathetic foot-passes which helped to ignite the performances of their full-forward ball winners.
Jason Doherty probably had his best hour in a Mayo shirt, something that was overlooked by Andy Moran's splendour. Cillian O'Connor chipped in for 0-3 from play that went unnoticed but each of his points were huge. It's unlikely Kerry will be strung by 1-5 from Moran this afternoon but it's vital for Mayo that Doherty is just as prominent.
They may also have to ask Aidan O'Shea to run the field and add his heft and skill to the attack. They need to try and curb the influence of David Moran and they have to eliminate the kind of turnovers which cost them both goals the last day.
Their half-forward line, for all its tracking back and approach work, needs to at least present a more tangible scoring threat. It was significant that Lee Keegan didn't try and run at Paul Murphy even after the Kerry defender picked up an early yellow card.
Formidable
Mayo looked formidable and comfortable every time they ran at Kerry. There are, at heart, a team crowded with brilliantly versatile defenders and there's an argument to be made for adding Paddy Durcan to the mix for one of the starting forwards. Fitzmaurice is brilliantly pragmatic and will do something to stop that quality to supply to the inside-forward line and will turn up the heat on Mayo's kick out even further.
Midfield is their platform and with Moran in such imperious form, Kerry will look to deepen their hold here. Fitzmaurice will also have noted how difficult Mayo found it to score in the closing 10 minutes once Kerry swamped their defence. The argument that Kerry have the greater scope for improvement is true. But it doesn’t automatically stand that Mayo will permit them to improve. It is equally true that Kerry have the more silken full-forward line but that won’t automatically translate from the stop-start show a week ago to the eye-catching machine which deconstructed Cork.
Mayo twice suffered huge momentum-shifts when they gave away those goals last Sunday. And yet they recovered. There is a chance that Mayo are an even better team than they know. Life doesn’t always have to be hard. Can they discover that? Avoid those gifts of goals, attack with more ferocity and don’t look back and they can manage their first championship win over Kerry in two decades.
Verdict: Mayo.
KERRY: B Kelly; Shane Enright, Mark Griffin, Killian Young; Peter Crowley, Tadhg Morley, Paul Murphy; David Moran, Anthony Maher; Stephen O'Brien, Johnny Buckley (capt), Donnchadh Walsh; Paul Geaney, Kieran Donaghy, James O'Donoghue.
Subs: Shane Ryan, Jack Barry, Fionn Fitzgerald, Barry John Keane, Jonathan Lyne, Jack Savage, Darran O'Sullivan, Tom O'Sullivan, Seán O'Shea, Bryan Sheehan, Gavin Crowley.
MAYO: David Clarke ; Brendan Harrison, Donal Vaughan, Keith Higgins; Lee Keegan, Chris Barrett, Colm Boyle; Séamus O'Shea, Tom Parsons; Kevin McLoughlin, Aidan O'Shea, Diarmuid O'Connor; Jason Doherty, Cillian O'Connor (capt), Andy Moran.
Last five meetings – 2017 – All-Ireland semi-final: Kerry 2-14, Mayo 2-14, Croke Park; 2017– AFL Division One: Kerry 0-15, Mayo 1-10, Austin Stack Park, Tralee. 2016 – AFL Division One: Kerry 2-13 Mayo 0-14, MacHale Park, Castlebar. 2015 – AFL Division One: May 2-11 Kerry 0-10, Fitzgerald Stadium, Killarney. 2014 – All-Ireland semi-final: Kerry 1-16 Mayo 1-16, Croke Park. Kerry 3-16 Mayo 3-13. (Replay) Gaelic Grounds, Limerick.
Odds: Kerry 4/7. Draw 8/1. Mayo 21/10.
Just the Ticket: €35 (stand). €25 (terrace). Juveniles €5. Concessions available Cusack and Davin stands.