Ulster Club SFC quarter-final: Glen v Errigal Ciaran (Sunday, 3.30pm, Celtic Park, live on TG4)

IN normal circumstances, possession is nine-tenths of the law. Tomorrow in Celtic Park, its significance is closer to ten-tenths.

Errigal Ciaran are a very, very good team with the football in their hands.

But compared to teams that tend to win Ulster Club titles, none moreso than reigning champions Kilcoo, they have to get better at not having it.

That's why a county final that they led by seven points at half-time almost got away from them. Carrickmore stepped up man-to-man, took complete charge of the midfield and squeezed the life out of Errigal. Carmen's running game created gaps and allowed them to haul the gap back to two.

Errigal won it because Darragh Canavan is a genius, basically. The ability and the vision to flick a bouncing ball right into the chest of Joe Oguz, sending him racing through for the vital second goal, was just enough of an intake of breath to get them over the line.

There's a natural inclination to take Errigal's history into account. On six of their seven provincial outings, they've won their quarter-final. That is way beyond norm for Tyrone clubs.

It has to be relevant too, because the rest of the county bears a weight of history that isn't hitched to Ballygawley backs.

More importantly, what they have on the pitch that most teams don't is five key attacking threats that all need watching.

Here's their attacking breakdown against Carrickmore.

Darragh Canavan: scored 0-3, assisted 1-2.

Ruairi Canavan: scored 0-2, assisted 0-2.

Tommy Canavan: scored 0-1, assisted 0-2.

Peter Harte: scored 0-1, assisted 1-1.

Ben McDonnell: scored 0-1, assisted 0-1.

Of their 2-11, those five players had a very significant hand in 2-10 of it.

Carrickmore were much better in the second half. How much of that was down to ripping up their match-ups and starting over with a whole new set it's hard to tell since Errigal couldn't get the ball to their forwards to test it. The winners' midfield collapse was the big issue.

Glen's often ferocious press on Slaughtneil's kickouts in the Derry final will have been noted.

Many seasoned observers gave the Emmet's a very good chance because Paul Bradley had completely altered how they were playing because they were dropping a lot deeper defensively than last year.

As much as anything they did last year, that was the day Glen proved they're a very serious outfit that can play it any way you bring it to them.

Their defensive match-ups were different from their norm. Goalscorer Cathal Mulholland picked up Shane McGuigan, a job that's ordinarily been Ryan Dougan's, with Michael Warnock on Sammy Bradley.

Warnock, outstanding in the past two seasons, will go on Darragh Canavan here. Glen will most likely leave Dougan on the brother Ruairi, which frees up Mulholland to go on cousin Tommy.

If Errigal can get enough ball then dealing with Ben McDonnell, Peter Harte, Joe Oguz and Peter Óg McCartan on top of the three Canavans coming at them becomes a big issue for the Derry champions.

The St Eunan's and Kilcoo games last year ought to stand to Glen in terms of finding ways to unpick massed defences. Central to that is Jack Doherty, who's been in sparkling form all championship and will take serious watching for Niall Kelly.

Everyone's been waiting for the day that Ciaran McFaul's absence from the team is felt but it hasn't arrived yet. Tiarnan Flanagan, Warnock and Dougan offer plenty of punch from deep.

With McFaul not there, the move of Ethan Doherty to half-forward rather than half-back was the signal that Glen's aim is to avoid being defensively exposed by winning the ball as high up the pitch as they can.

Conor Glass and Emmett Bradley offer them the aerial platform to go after Darragh McAnenly's kickouts.

Errigal couldn't win a ball in the second half against Carrickmore. Joe Oguz, Ben McDonnell and Peter Harte were all outstanding with the ball in hand but none of the three did enough to break the midfield stranglehold.

That's really it the game here. In the post-match analysis, you'll almost certainly be able to draw a straight line from how Errigal's kickouts go to how the game goes.

Glen will be brave and go after the ball.

If Errigal can find enough ways out, if they could even get to 70 per cent on their kickouts, if they're willing to die on that ball when it falls in the middle then their attacking class on the ball will have its platform to write the story, and they will win.

But it's a big if. Too big, most likely.

Glen should earn enough control of the middle to earn enough of the ball to earn a narrow win.