Eighteen AFL teams became eight just three weeks ago. Since then those eight have been whittled down to the final four contenders for the 2024 premiership.

Each of the four teams have — at one stage or another — held favouritism for the flag. With just two weeks of footy left in the season it is truly anyone's competition. Each of the teams are generally solid across the board — as very good football teams tend to be.

Each of these four contenders — Sydney, Port Adelaide, Geelong and Brisbane — have particular parts of their game that need to go right to lift the flag.

These are elements that each team needs to get right this week in order to make the grand final next week.

Sydney’s shot generation strength

As the minor premier the Swans arguably have more clear strengths than anyone left.

Despite a late season wobble, the Swans entered finals with the number one ranking next to their name. They were in the top three in scoring from both the front half and back half. Their defence wasn't that bad either.

In anyone's terms they were a solid football team across the year, worthy of the title of minor premier.

But let's focus on something that's not traditionally associated with the Swans in recent years: their attack.

The Swans finished the year with the most total points of any side. They were also the most efficient at turning inside 50s into points. Sydney swooped in the goals no matter how you break it down.

But how the Swans went about it was a little more unusual. While the Swans run three tall forwards at most times, they have languished near the bottom at taking marks inside 50.

Instead, it's the potent small forwards and midfielders pushing forward that do a lot of the damage. The Swans use smaller options like Heeney, Hayward, Papley and Warner to hit the scoreboard on the run.

The Swans also aren't afraid to bomb away from deep. Only six teams score more than a goal a game from more than 40 metres out on the run. Sydney is the only side going at two goals a game from such a distance.

Instead of acting as usual focal points for their attack, the talls act as foils and spacing options for their smalls. But if too much attention is diverted, events such as Joel Amartey kicking nine goals in a game can occur.

In short, if the Swans can get their forward line going — unlike in their round 20 game against the Power — they'll stand a very good chance at staying alive for one more week.

Port Adelaide’s ball-winning prowess

Two weeks ago Port was humbled in a variety of ways by Geelong. Most striking was how the game played out through the contests right across the ground.

Not only did Geelong gather more ball from contests at ground level, but they also used it more effectively. Geelong's win was comprehensive, but their 91-77 victory in winning disputed ball at ground level more than helped them on their way.

There is a part of this that is no surprise. Port was one of the strongest teams at winning the ball at clearances, but the weakest at winning the ball post-clearance. When Port flies in defence they prefer to mark and not spoil. They are also not the most aggressive side at jumping handball lanes.

Last week — on paper — presented Port with their kryptonite. Hawthorn came into their semifinal as the strongest ground ball team in the competition and were metaphorically flying. Best against worst usually isn't tough to predict.

However, Port defied expectations. The Power more than did the job against the Hawks at ground level. The 104 to 94 victory by the Power was one of their strongest ground ball wins of the year.

Port's players worked hard on their contest positioning — spacing around the ball more effectively and working at hitting the drop of the ball at speed. It was clear that Ken Hinkley and his team focused hard on this particular part of their game. Hawthorn played Port more conventionally than Geelong did at contests, which suited the Power perfectly.

Port Adelaide's strongest win of the year came against Sydney — the side they face to make the final week of the season. That 112-point win was powered by a giant 86 to 62 ground ball advantage. On paper Port match up with Sydney well in this area of the ground given how both sides like to approach contests.

If Port are to make a third AFL grand final, it'll likely be powered by their ability to dominate the ground ball game.

Geelong’s rock solid defence

Most fans were in awe at the 138 points that the Cats piled up when beating the Power on their home deck in week one of the finals. That makes sense — goals are exciting, and intercept marks aren't.

But over the closing stretches of the season it was the other end of the ground that powered the Cats towards this vaulted position. Geelong's defence has long been a strength for Chris Scott. But with shifting parts in the forward half of the ground, this strength has become a reliance.

Led by Zach Gutrhrie, Mark Blicavs, Jack Henry and Jake Kolodjashnij, the Cats have effectively shut down their defensive 50. The defence has shifted away from attacking hard from defence — the Cats sit near league average at scoring from intercepts over the past five games.

The Cats sometimes move a spare player back from stoppages after the contest breaks free — often former All-Australian defender Tom Stewart. This creates an extra defensive number to prevent sides from scoring in transition. They also don't overcommit on the counter attack and communicate effectively. They get most of the basics right in defence — key for a side who is primed to succeed in September.

That defensive ability has kept them in games where they don't win territory. If they do manage to win the field position and possession battle it can blow teams out of the water.

Brisbane’s front half game

If you listen to enough coaches talk, the words "we want to be a front half team" will likely come out sooner or later. There's a good reason for that — territory often dictates the path of play in football.

Not only is Brisbane a front half team, they are one of the best front half teams in the competition. At their best, the Lions don't have any weak links forward of centre, and can attack goals via their opponents' weaknesses.

That ability to create repeat chances at goal — either via stoppage or turnover — is critical for the Lions to succeed. The Lions have dealt with a number of prominent injuries to their defensive stocks through the year. An effective team defence higher up the ground has helped Chris Fagan deal with these issues, as has an increased focus around stoppage.

Brisbane's goal kicking woes have been well documented over the year. They've also been on full display in their two finals. It's not just that they kick a lot of behinds, but more that their let-downs have come from comparatively simple positions.

The Lions sit at about league average in converting more difficult shots — set shots outside 40, from the pockets, and shots from general play. But they've been easily the worst set shot team in the league at kicking at goal from straight in front of goals within 40 metres — the gimmes. Brisbane has been a full 0.55 points worse per shot than the "expected score" in this location.

Their Round 6 loss to Geelong saw the confluence of these two problems. Their front half trap largely broke down, with the Cats able to score 38 points from their back half. That's one more point than the Lions kicked in total for the game from anywhere.

That's partly because the Lions firmly didn't have their kicking boots on. 

Brisbane kicked 4 goals 13 behinds in the game, missing shots easy and hard alike.

If they can defend the ground more effectively and kick the ball like a normal team from straight in front they stand a chance of righting that result.