The clash of the Titans will be a match to remember
So much of today's All-Ireland quarter-final between Donegal and Mayo depends on opposing Totem poles Michael Murphy and Aidan O'Shea.
Here, Peter Canavan assesses the key aspects of their games.
There are plenty of distractions for Murphy, but it is never about him. He shows remarkable maturity and modesty for a young man and is totally centred around winning for Donegal.
That's very appealing from a manager's point of view and it's why the players have so much respect for him.
They look to their leader when things aren't going well and Murphy is not found wanting in this regard. When they needed to get off to a good start in the 2012 All-Ireland final, for example, Murphy got the goal against Mayo.
Despite struggling against Derry in the Championship last year, he stepped up to the plate with a sideline free. Against Armagh, he inspired the late rally in the quarter-final. He did the same this year with his free-taking against Tyrone in Ballybofey.
If Murphy has the demeanour of a born leader, then O'Shea would be classified as one that is emerging.
While he is more charismatic than Murphy, I find it surprising that he has yet to captain this Mayo team.
He is dedicated, unselfish and leaves it all on the pitch.
There are times in games when players have to drag their county over the line. He is going to have to show this kind of leadership if Mayo are going to win the ultimate prize.
Has winning an All-Ireland satisfied Murphy's hunger? Absolutely not.
Your appetite can often be measured in turnovers, the amount of tackles made and the willingness to win dirty ball on the floor.
Murphy's tackle count this season has been high and when he tackles, if he doesn't get the ball, he gets something.
You could put a question mark over one moment this year, against Monaghan. After giving the ball away late, he allowed himself to be overtaken.
As for O'Shea, he appears ravenous. He looks sharp and wants to be involved in every opportunity regardless of the scoreline. There appears to be a ruthless streak in him. His pursuit of excellence continues.
We are not comparing like with like here. Murphy has captained his county, won his All-Ireland medal and has enjoyed all the rewards the game can offer. The competitor in O'Shea makes him hell-bent on acquiring all of that.
When it comes to skill repertoire, Murphy is right up there.
Be it fielding, ball control, passing by boot or hand, scoring - it's exemplary.
The range in his kicking ability is matched only by perhaps Bryan Sheehan. His point from play against Galway highlights his strengths perfectly; the timing of the jump, his hangtime in the air, the catch itself and then the kick over his shoulder from 35 metres.
The same can be said of so many of O'Shea's plays this year. He too is so confident when in possession.
For such a big man, it is remarkable how good his ball control is.
An area of his game that his has worked on tirelessly is his finishing. That has shown in the nature of his goals this summer. He now displays maturity and patience and his finishing is clinical.
His physique means that he cannot resist taking the ball into the tackle too often. This leads to bad habits. Against the top teams, this is not going to be easy. He is going to be double-teamed in the remaining games, leaving space for others around him. If he can find them, it will be a weapon for Mayo.
Where Murphy will play depends on the Mayo set-up. He has proven that he can turn games in a flash in full-forward. If he moves out the field, he is easier to man-mark.
For the goal against Mayo in 2012 and the performance last weekend against Galway, the key was the space around him so he could run and jump.
When he went into full-forward against Tyrone, space was denied and he was forced to spend more time around the middle. However, he is a perfect link-man.
So many teams that have won All-Irelands have someone who breaks up play and is known as a workhorse. Ironically, Donegal's best player is their workhorse.
O'Shea's new role leaves it hard to form an opinion on the back of two facile wins. At the start of the year I suggested this move was something Mayo had to do, as they lacked a ball winner.
This gives them a serious attacking option they didn't have in previous years. It's a good call but a big one.
O'Shea may be tempted to get out to midfield, especially if they are struggling in that area. It will be a test of the managerial relationship, what flexibility Pat Holmes and Noel Connelly have given O'Shea to make this decision. Can he be patient and wait for their period of dominance?
This is about knowing when a team needs you and knowing when a game is going against you. Can you break it up? Can you influence the course that the game is taking?
Murphy can. If it means making a rash tackle and getting involved in a shoving match, he is able to do that.
It's not done out of vengeance or bad temper, but with cuteness. When a game is in the balance, players wait for something to happen. On a lot of occasions, that something has been created by Murphy.
You don't have to go too far back for a brilliant example of his awareness, as last weekend he palmed down a ball on a plate for Ryan McHugh's goal against Galway.
Not enough is made of his decision making. Seldom do you see him shoot when he should have passed.
It is something O'Shea has to work on. He is still learning and is capable of matching Murphy in this regard. Perhaps Mayo have been lacking game sense.
By taking the ball into the tackle so many times, O'Shea is guilty. His redeployment will give him a greater understanding of what forwards require if he should ever move back again.
He has a good grip of what is required, he just doesn't have the influence of Murphy. We will be in a better position to judge at the end of the season.