The season has ended with familiar scenes of Dublin celebration, and congratulations to all involved; they are a superb team. This year's All-Ireland championship has produced compelling rivalries in the shape of Dublin, Mayo and Kerry. Eamonn Fitzmaurice will have learned a lot from both All-Ireland games. Stephen Rochford and Mayo will spend the autumn figuring out why they didn't get over the line. Even now, the forces are beginning to conspire.

The 2016 All-Ireland finished on a worthy note, with a match that was far from unblemished but which contained plenty of wonderful moments and an atmosphere of sustained courage from both sides. The emotion was entirely real.

The changes before the game caused the first real drama of the occasion. It was probably 20 minutes before throw-in when I heard. The Mayo goalkeeper switch was really difficult for me to get my head around. Mayo's belief clearly was that Rob Hennelly could do something that David Clarke could not. In theory, I am okay with that kind of thinking because that's what management is there for. What was lost on me was that Rob hadn't played in the previous game whereas David had an All-Ireland final under his belt and would have had that level of relaxed thinking.

The other issue, which unfolded as the match went on, was; what was this added ingredient that Rob Hennelly was meant to bring? Because whatever the intention, it didn’t work out and it proved to be a harrowing experience for Rob and backfired badly on Mayo.

It was a massive decision to make. Clarke saved two one-on-one goal chances against Brian Fenton and played really well in the drawn game, for my money. Removing him from the equation presented more questions than answers.

Jim Gavin’s changes reflected his mindset. He went into lockdown after the drawn match. Dublin looked stung afterwards, individually and as a team and the selection for the replay illustrated that.

I think they also looked at tactical substitutions whereas Mayo made reactive changes. In other words, Gavin had predetermined his substitutions to some extent: they knew Cormac Costello and Bernard Brogan and MD Macauley would go in and when they would go on.

And imagine you are Paul Mannion or Paddy Andrews or any other player starting the game, knowing those guys are breathing down your neck. As a manager, you know you are going to get an extraordinary effort from your starters and that at the very least they will run their markers into the ground.

So when Costello and Brogan came in, the Mayo players had been spent for an hour and it made it easier for high-octane Macauley to rampage through the middle, which is the beginning and end of his game. Dublin started like a whirlwind and that represented a return to their core values. They looked to attack quickly and kick directly inside. And as soon as they had the ball over the bar, they hustled to shut down the Mayo kick-out options within three seconds. That was one lesson they learned from the drawn match.

They started in awesome fashion. They looked sharp and slick and aggressive all over the pitch. There were blots – I did feel John Small committed a hand trip on Andy Moran and they gave Mayo a way back in through two fouls.

Also, their decision-making was rushed. That was the strange thing. It was as if they were so pumped up to show people that the drawn game wasn’t the real “them” that it had an impact on the final ball. And Mayo got their turnovers and did what Mayo do, which is to attack games with an absolute integrity and self-belief.

One moment stands out for me. Lee Keegan played a ball into Andy Moran that was absolutely sensational; Cusack stand side under pressure and he wrapped his foot around it. It was a perfect ball which highlighted the repertoire of skills which the Westport man brings to any match. It’s significant in the broader context. There was such debate around the Keegan/Connolly match-up that I felt the best thing Keegan could do for the replay was to play more football and get up the field. And he did that splendidly in the first half hour, scoring one of the goals of the season in the process.

I remember jotting a note down also: "Jonny Cooper absolutely excellent. Best player on field. Taking game to Mayo. Getting in front of his man and really transitioning". Then I looked up and I couldn't see Cooper anywhere and James Horan told me he had just been black- carded. I couldn't believe it. Lee Keegan followed him shortly afterwards.

So in a very real and terrible way, the black card dominated the All-Ireland football final. Kevin McLoughlin was fortunate, I felt, not to go for his tackle on Kevin McManamon and as I mentioned, John Small was blessed. But the Lee Keegan decision proved without question that the black card is flawed. Eugene McGee, one of its architects, has said that it has cleaned up the game. In my opinion, the black card is ruining the game. You simply cannot have two of the best players in the sport leaving the game in an All-Ireland final – the biggest game of their lives – for what were, at best, fouls that merited free kicks.

Technically, Cooper's was a black card. But the ball wasn't even in play at the time: it was a nothing-moment in the middle of the park. And Keegan's indiscretion was much greyer. He grappled with Diarmuid Connolly: he had his hand on his shoulder but they fell together. Did he drag him down? Impossible to say. It was a foul, yes. Was it a yellow card foul? I'm not sure.

You couldn’t say with certainty that it was a black card offence. There was no cynical, deliberate intent to drag his opponent to the ground.

This is the problem Maurice Deegan is faced with. Eighty-two thousand people; Diarmuid Connolly jumping up waving for a card. Lee was walking a tightrope coming into the match; he was on a short lease so any borderline call was likely to place him in a tough position. And he paid a heavy, heavy price. Mayo paid a heavy price.

See, the black card will favour the team with the deepest squad. Dublin can bring in replacements that are arguably better than the guy who is coming off. Mayo can’t. Most teams can’t. Tipperary’s Robbie Kiely’s case is still in my head after his black card in the semi-final. That was the game of his life. So when Lee left the field, a part of me was thinking: I’m not sure Mayo can win this without Keegan. Another part of me thought: this crowd never give up. So I figured the match would go down to the wire.

But Lee Keegan is Mayo’s flash of inspiration and their lightning conductor. He is a brilliant defender, he has speed to burn, he is a brilliant ball carrier, he can pass and score. He is at the top of his game. He was literally irreplaceable for Mayo. To make it clear, I am blaming the black card institution here, not Maurice Deegan. I looked at Maurice’s face and he was gone. He was like a guy that had lost his own train of thought. Do referees want to be the guy who dismisses the best player on the field? Of course not.

There is a scene in the movie Friday Night Lights and you just see the tackles and the hits and the exchanges at close quarters; it is fast and furious. Well, that is championship football. And if you, as a referee, are caught with your eyes elsewhere, it is impossible to process what has happened. But the GAA is asking referees to immediately decipher if a tackle was cynical and full of intent.

Add in the pressure, the intensity, the noise, the psychology behind the decision, the players going berserk, the fact that his view may have been obscured. And think that having to send a guy like Keegan to the line doesn’t play on his mind? Of course it does.

It has to go. The sin bin is not a perfect solution but at least it doesn’t ruin a player’s day or a team’s chances. He loses 10 – or even 15 – minutes; he has to go; the team is punished. But he gets to come back in and atone for it. The Keegan- Connolly duel was beginning to enter a new realm on Saturday. And we will never know how it should have turned out.

So Dublin are in positive mode and are looking to run the ball but they don’t have the same support off the shoulder. For instance, James McCarthy is steaming forward. Normally, he drops the shoulder and steps inside knowing he can lay it off left or right. That wasn’t happening: the ball carriers were getting isolated. Dublin weren’t fully back to themselves.

For me, they were still meticulous in their approach. In a previous column, I referred to this change and I think they have morphed into that more cautious, deliberate team now. That buccaneering, free-flowing scoring side may be a thing of the past. They won’t do that all the time anymore. They have become instinctively deliberate. Their running game is a more measured, percentage-based type of attack. They had opportunities to deliver direct ball to their inside players on Saturday but they passed up more often than not and recycled the ball.

Now, this Mayo team has limitless reserves of bravery. And their response to Dublin’s opening salvo and to the second-half penalty was terrific. They have taken a radical step forward in terms of their intensity. While they defended Dublin man-to-man, they had the facility to switch into a zonal-based cover in the defensive third of the field. As a result, their turnover ratio was exceptional.

Regardless of the quality on show – and there were some fantastic moments in the game – this was proper championship football. Everyone was prepared to put everything on the line. And both sides created some terrific scores – Tom Parsons made a fetch and played a pass to Diarmuid O'Connor for a brilliant second-half point.

Stephen Cluxton was exceptional on Saturday evening. What I loved about his performance here was his selection of kick outs. If they didn't come off, Dublin could have been in trouble. But they were immaculate. They were so clean and accurate and his ability to deal with pressure was a defining aspect of the game.

The match was in the melting pot for a long time and then Dublin began to show what proved to be their trump cards. This was the other key aspect. The changes before the game came to bear when the championship was up for grabs. The pre-emptive ruthlessness paid off.

Michael Fitzsimons had to wait until Saturday to get his chance to start and he was excellent: so steady and composed. It was a good decision by Gavin to play Fitzsimons.

The timing of the substitutions was crucial and all three introductions paid instant dividends. The link between Macauley and Brogan for that point had a training ground look about it. Now, Dublin were still very wasteful. They spurned a huge number of opportunities and were not clinical – with the exception of Costello. He caught three and kicked three. It pushed Dublin into a place that Mayo just couldn’t reach.

Costello brought a combination of energy and execution. The Mayo defence was tired and digging deep and he was fresh and eager to impose himself and it worked a treat. He put himself in a dangerous position – at the top of the D – and kicked the ball over the bar. It was simple. And for the last 10 minutes, then, Dublin had 14 men behind the ball.

That was another lesson from the drawn game. They were not going to permit Mayo to cut through them again. So I think they will be happy with their day’s work. They scored 0-8 from play; not a huge return but Mayo’s defence was brilliant here.

Twice, Mayo took Dublin to the point of vulnerability. So did Kerry. That will give hope to other teams; it will give hope that the champions aren’t unbeatable.

And yet, unbeaten they remain.

So if Rory O’Carroll comes back in and a guy like Fitzsimons stays in and Jack McCaffrey returns, then whatever perceived thinness existed in Dublin’s defence this summer may well disappear.

So it is a scary prospect.

But the bottom line is that they have four All-Ireland titles in six years because they have more scoring forwards than anyone else. They seem to have that level and variety of natural scoring options. The class can come from different areas on any given day. Conversely, that may be the key reason why Mayo have failed to win a championship in that period. So Mayo need to find an alternative way to attack. They have looked to take Dublin and Kerry on in a very noble way but they have to go a different road.

If I was in Mayo shoes now, the first thing to do is to hold on to key players. Keith Higgins is top of that list: he is absolute quality. And I can see why players say: 'look, this isn't working out and I have to get on with my life'. But Keith still has the pace in his legs and should play on while that remains. He will be retired long enough. A player like Higgins can define levels of effort and performance within county teams so if he falls out of the system, it is a massive, massive loss to Mayo.

Furthermore, I feel Stephen Rochford should retain everything they are doing right now: they should further develop their kick out and defensive strategy.

Here’s the thing to which Mayo must reconcile themselves. They don’t have marquee forwards in abundance.

But so what? They still have very good forwards. That is plenty to work with.

So can they create a strategy which will enable them to create more scores? This now, becomes their winter project. It didn’t look as if the work had been done on concerted attacking, as if there was a plan.

For instance, they did go with two big men in the square in the last ten but it was more like: ‘okay, we are coming down the stretch....let’s get the big men in there and see what happens’. It is not enough to do that. For me, it is about repetition on the training field night after night so the angle of the ball, the runners, the target; everything is concerted.

The focus on Aidan O’Shea is unfair. He has an almost impossible task with Mayo right now. Regardless of ability, if Mayo had Kerry’s decision-making quality in the final third of the pitch, they probably would be All-Ireland champions right now. Just that capacity to see the open man and that pass-appreciation – the dink ball safe side two metres beyond the defender to your team-mate so he can win the ball . . . if Mayo had that, it could be a different conversation today.

The burning question: Will Mayo win an All-Ireland? It’s difficult. I believe they can if they are willing to further adjust.

They did succeed in repairing the leaks to their defence. Their age profile and strength is as good as what is out there. So the last piece of the jigsaw now is up front. Get to the drawing board and design a plan to get more scores out of their key assets, which is predicated on guys like Keegan, Parsons, Durcan, Vaughan and Higgins bombing into the scoring zone from deep.

That’s where Mayo should be shooting from, in my opinion, not the conventional seek out the forward with the long ball inside route. And can they add these layers of complexity – how to get frees in dangerous areas and get handy points and carry a real threat inside to occupy the defensive full back line? Can they learn to play high percentage efficient football underpinned by a connected offensive strategy?

Can Dublin win more All-Ireland titles? Yes, but that too becomes more difficult. I believe they will fear Mayo if Mayo can do all of the above and retain that incredible drive of theirs. Because Dublin know in their hearts that they were dragged deep into the trenches for long spells in both those games. So if Mayo come back ready for more and have added yet another dimension or two to their game, they will present an even greater challenge.

Then you have Kerry aching to set the world to rights. These are wonderful rivalries. We are lucky to have them.