LET'S do the maths to put Saturday afternoon's round 20 clash with Collingwood at the MCG in perspective.

Port Adelaide is ranked 11th. It has an 8-10 win-loss record - and, by the mathematics, must succeed in all four of its remaining home-and-away games to pass the 12-win threshold that generally achieves a top-eight finals berth.

And there are three teams to leapfrog into the upper echelon. Port Adelaide's destiny is in many hands today:

WESTERN BULLDOGS (eighth, 10-8, 111.9 per cent): Geelong, Fremantle, Greater Western Sydney and Hawthorn.

ST KILDA (ninth, 10-8, 103.6): Hawthorn, Geelong, Brisbane and Sydney.

RICHMOND (10th, 9-1-9, 114.5): Brisbane, Port Adelaide, Hawthorn, Essendon.

There is a case to be made that the Western Bulldogs, St Kilda and Richmond might find no more than two wins in the next month ... and this would leave the door truly open for Port Adelaide.

But it is one hurdle at a time - and Collingwood, a surprise contender for a top-four finish, is one of the most-testing challenges in the game today. It certainly is the team that will play to the final siren with Collingwood having extended its winning streak to nine by claiming victory in eight games this season by two goals or less.

This is Port Adelaide's first encounter with Collingwood in any football since July 23 last year - and much has changed on both fronts in the following 12 months.

Collingwood has a new coach, Craig McRae who has recast the playbook to emphasise a more attacking (and more attractive) game.

Port Adelaide has its own new ways, some built out of necessity for change after the 0-5 start - and the lack of a dedicated ruckman after Scott Lycett was lost to a shoulder injury in round four.

"While we are still a mathematical chance, we will be going out there wanting to beat Collingwood this week. What happens outside of that (with fellow contenders Richmond, St Kilda and the Western Bulldogs) is out of our control. We just control what we can. If that door to the eight stays ajar - I know the odds are against us - while we are living and breathing, we will keep going for the win.

"Regardless of where we end up in a week, a fortnight or three weeks, every week we go out there wanting to win."

Port Adelaide captain and defender Tom Jonas

NEW THEME

IN recent Port Adelaide-Collingwood games, those that had Nathan Buckley commanding Collingwod's agenda, the opposition's challenge was to find a way to endure and overcome a defensive vice. New Collingwood coach Craig McRae has not betrayed defence in his playbook, but he has put a new, positive emphasis on attack.

Collingwood has lifted its average score by more than two goals this season (to 85 points from 71 last year).

Collingwood opened the season breaking the 100-point barrier against Adelaide and St Kilda. Its highest score of the year is the 115 points against Gold Coast in round 7.

On defence, Collingwood this season concedes on average 80 points - and the 85-80 average scoreline does tell the story of a team that has worked (with wins) through seven of its past nine games being decided by two goals or less and the past four by five, seven, five and four points.

"Collingwood play attacking football. We are good defensively. Hopefully, that plays into our hand a little bit. They like to play really quick, take the game on - at a risk at times. If our defence is on, as it has been, we can cause some turnovers. Our main concern this year has been converting those inside-50 (opportunities created on rebound or turnovers). We need to score. We have to make the most of those opportunities with scores."

Port Adelaide midfielder Ollie Wines

NEW POWER

IT is remarkable how both Port Adelaide and Collingwood have coped while missing lead ruckmen Scott Lycett and Brodie Grundy, respectively. The great duel that dates back to the 2018 AFL grand final (when Lycett was with West Coast) will not resume this weekend. Lycett is overcoming his shoulder injury; Grundy is in the VFL, building form after being sidelined by a knee injury (the ruckman's curse of a knock to the posterior cruciate ligament).

Port Adelaide is sticking with the Jeremy Finlayson-Charlie Dixon combination, the key forwards revolutionising ruck work with their groundwork. And there is half-forward Sam Powell-Pepper to pinch-hit when needed.

Collingwood is working Mason Cox and Darcy Cameron.

"Charlie has been phenomenal - and paired with Jeremy they are a dynamic duo," says Port Adelaide captain Tom Jonas. "We might not win the hit-outs, but the damage they do when the ball hits the floor has proven to be a great combination for us. It is not traditional, but it is certainly the way the ruck game is working for us and we are very happy with that."

Finlayson has certainly shown his passion for ruck work. Dixon has shown his passion, full stop.

"You take a fair battering," says Port Adelaide midfielder Ollie Wines of the physical demands being asked of Dixon and Finlayson. "At the moment, Jeremy and Charlie are doing an enormous amount of work as forwards being asked to play in ruck. A huge amount of work.

"We are willing to sacrifice the hit-out in the air to gain that extra player at ground level."

And here Port Adelaide is finding that added man winning clearances is making a difference on the scoreboard. In the past two matches, Port Adelaide has outscored the league-leading Geelong and defending premier Melbourne at stoppages.

"Charlie, Jeremy - and Sam Powell-Pepper have been outstanding," says Port Adelaide midfield coach Brett Montgomery. "What we have done is, we have challenged the competition in a way of ruck play and outnumbering the opposition at the ground-level hunt for the ball. By circumstance (the shoulder injuries to Scott Lycett and Brynn Teakle), we have found something new."

Collingwood coaching director Brendon Bolton certainly has taken note that Port Adelaide has "some good on-ballers ... you only have to look at the likes of Travis Boak and Co."

"They have pushed two very good teams (Melbourne and Geelong) in the past fortnight," Bolton said. "We are under no illusions on how it is going to be a tough game. And then in defence Port Adelaide has Aliir Aliir with his intercept game. We are going to need to manage that Port Adelaide midfield (on the ground) - and do enough in the air this week because those are a couple of big strengths of Port Adelaide."

Collingwood ranks last of 18 for scores from centre-bounce clearances. But it is the league's best team for winning one-on-one contests.

"It's not real hard ... I keep telling the ruckmen that."

Port Adelaide vice-captain Ollie Wines on his appreciation of ruck work - after winning a centre ruck duel and the resulting clearance against Geelong at Adelaide Oval last week.

NEW ROLES

FIRST it was Connor Rozee who filled the need (amid the absence of both Robbie Gray and Orazio Fantasia) as the opportunist, small forward working around the goalsquare while Sam Powell-Pepper tormented defenders at the top of the 50-metre forward arc. But Port Adelaide could not afford to keep Rozee out of the midfield rotations, particularly the starting rotations.

(For the record - During the first five rounds, when Port Adelaide fell to a 0-5 win-loss count, Rozee had just two votes from the coaches in their annual association award. Since round 6, Rozee has polled 66 votes to rank seventh on the leaderboard).

Now, the question is: Can Port Adelaide afford to have fellow young midfielder Zak Butters recast as the small forward working next to key forward Todd Marshall - a tandem of a new generation?

"We have done that with Zak, Connor, Travis Boak ... even Ollie Wines. All our midfielders at some point have to spend time forward," answered Port Adelaide senior coach Ken Hinkley. "And Lachie Jones. Jed McEntee can step up. Powell-Pepper keeps growing. There is plenty of flexibility in our team.

"Zak has played as a forward pretty much most of the last six-to-seven weeks. We structure our game up slightly differently with where Zak may or may not appear to be at times. Zak can be damaging in both roles (midfielder and forward) ... as the others. They all can be damaging whether they are in the midfield or forward."

Prepare for a strong attacking theme from both midfields.

MILESTONE MEN

DESTINY has a strange way in Australian football. Two years after they shared their 150th AFL milestone, captain Tom Jonas and vice-captain Ollie Wines pass the 200-game marker in the same game.

Jonas returns to the MCG where he played his first game - as did Wines. The symmetry is extraordinary but completely aligned.

Jonas started in round 21, 2011 - against Hawthorn with a hefty defeat while Port Adelaide was deep into the so-called "dark chapter".

Wines began in round 1, 2013 - against Melbourne with a notable win that marked the start of a new era, on and off the field, for Port Adelaide.

"I will never forget. Go to the MCG, tag Luke Hodge, lose by 26 goals ... that is a baptism of fire. And fined my entire match fee for bumping into an umpire. That is a memorable welcome to the AFL."

Tom Jonas

TIME FLIES

THIS is the 25th anniversary of Port Adelaide's first season in AFL company. It began against Collingwood at the MCG on March 29, 1997.

This is the 52nd time Port Adelaide has played an AFL match on the MCG (where it had some historic moments as an SANFL-based club). The win-loss count is 22-28 with one draw.

The first two games at the G this season were ... well, symbols of Port Adelaide's season. The first - against Carlton on April 17 - ended in a three-point loss after a nine-goal second half almost wiped out a 49-point deficit at half-time. The second - against Richmond on June 9 - ended in a 12-point loss after the Power rallied late to claim a fourth quarter lead, but could not hold on in close contest.

Port Adelaide has won its past three against Collingwood - and seven of the past nine.

IF IT GETS TIGHT

COLLINGWOOD has won nine games in a row - and the past five by 11 points (against Greater Western Sydney), five (Gold Coast), seven (North Melbourne), five (Adelaide) and four (Essendon). Since round six, Collingwood has won eight games by 12 points or less (after losing three in a row by 13, 13 and seven points). No AFL team has been so fixed on the right side of luck since 1989.

Port Adelaide this season has won two games decided by a kick (the one-point win against St Kilda in Cairns and two-point triumph against Gold Coast at Adelaide Oval). But there is a long list of narrow defeats - of them: 11 points to Brisbane at the Gabba, four points to Adelaide in the Showdown, three points after giving Carlton a big start at the MCG, 12 points to Richmond at the MCG, eight points to Fremantle in Perth and 14 points to AFL premier Melbourne at Alice Springs and 12 points to league leader Geelong at Adelaide Oval in the past fortnight.

"Collingwood has been the opposite of us - they have been able to get over the line (in tight finishes)," Jonas said. "That comes from the way they attack the game. When the game is on the line, they become bolder and braver. They really take it on. You make your own luck. The way they play the game has certainly allowed that to manifest (with four consecutive wins by seven points or less in the past month).

"We need to keep playing out brand of footy - and do it for four quarter. We talk about the contests. We talk about executing our ball movement and skills goin forward - and maximising those opportunities. It will be an incredibly high-pressure game."

Port Adelaide captain Tom Jonas

FIXTURE NOTE

JUST saying ... Port Adelaide last hosted Collingwood at Adelaide Oval in round 21, 2017. Since then, the Port Adelaide-Collingwood matches have been played at the MCG (twice), the Docklands in west Melbourne (twice) and at the Gabba in 2020 with another game that was originally scheduled for the MCG in round 5 before the COVID pandemic temporarily shut down the AFL home-and-away series.

Port Adelaide has won three of these five games away from home.

QUOTE OF THE WEEK

"NO-ONE would have guessed that for the past seven weeks Jeremy Finlayson has been the No. 1 ruck in the competition. And when you dive deeper (into the statistics) he has spent 72 per cent of game time in ruck in that time. What this has done for Port Adelaide is significant.

"Since Jeremy Finlayson became Port Adelaide's No. 1 ruckman - with Charlie Dixon in support - in round 13, the numbers are - clearance differential has gone from No. 8 to 4; points from stoppage, from No. 16 to 3; and contested possession differential, from No. 13 to 5. So I am not writing Port Adelaide off as a finalist. They have outscored Geelong from stoppage.

"Finlayson and Dixon have given Port Adelaide a different look through the midfield. They are last for hit-outs, but it is amazing what they can do at ground level. They are getting it done. It is a point of difference they can continue to roll with."

Leigh Montagna, former St Kilda player and Fox Footy analyst

BIRD SEED

(the small stuff that matters most)

Where: MCG, Melbourne

When: Saturday, July 30, 2022

Time: 1.15pm (SA time)

Last time: Port Adelaide 14.13 (97) d Collingwood 10.9 (69) at the Docklands in Melbourne, round 19, July 23 last year

Overall: Port Adelaide 18, Collingwood 16

Past five games (most recent first): W W W L L

Scoring average: Port Adelaide 83, Collingwood 90

Tightest margin - Port Adelaide by one point (88-87) at the MCG, round 14, July 2, 1999; Collingwood by two points (89-87) at Football Park, round 20, August 18, 2006.

Biggest margin - Port Adelaide by 67 points (125-58) at the MCG, round 11, June 5, 2016; Collingwood by 138 points (159-21) at Football Park, round 20, August 6, 2011.

By venues: Adelaide Oval (2-0), Football Park (7-6), MCG (7-5), Docklands (1-5), Gabba (1-0).

By States: South Australia (9-6), Victoria (8-10), Queensland 1-0.