No matter how many 'innovations' are crowbarred into the game, some things never change.

The six again rule and its implementation on ten-metre infringements triggered a barrage of points and blowouts this season. Five players scored 23+ tries in 2021 after only six had hit the mark between 2016 and 2020. Reuben Garrick became the first player to kick 100 goals and score 20 tries in a season. The gap between good and bad has never been bigger and the interest in games beyond the 30-minute mark diminished far too often throughout the year.

However, here we are preparing for yet another NRL Grand Final featuring two of the top three defensive teams in the competition.

Perhaps more important now than ever, defence will win the 2021 premiership.

The 2015 North Queensland Cowboys are the only side since 2005 to win the premiership with a defence ranked outside the top three. This year, it's the Penrith Panthers' historically good defence taking on an improving South Sydney Rabbitohs.

RELATED: Stats Insider's 2021 NRL Team Of The Season

The Panthers have been a defensive juggernaut all season. Nathan Cleary kicks the Panthers out of trouble through his NRL-high 543 kicking metres per game and pins the opposition in their own end. They make things incredibly difficult for the opposition to work their way up the field. On the occasions they are forced to defend their line, Penrith rarely cracks.

Their 11.6 points per game is the second-best defensive number in the NRL era and backs up an already impressive 11.9 points conceded per game in 2020. 

*Top 20 defences since 1998 (Premiers in yellow)

It's a different story for the Rabbitohs who will need to overcome the over-stated "no team has ever conceded 50 points and gone on to win the premiership" stat. Twice the Bunnies conceded 50 points as they allowed the opposition to score 22.9 points per game across the opening 12 rounds. However, their 14.2 points conceded per game since then suggests this Rabbitohs defence is of premiership-winning quality. That number would see them sneak into the list of Top 20 defences since 1998 had they maintained it all season. 

As expected, the Panthers and Rabbitohs are two of the best attacking teams in the competition so their elite defences will be tested. 

The Panthers take a grinding and patient approach to their attack. No team averages more tackles inside the opposition 20-metre line than their 31.6 per game. Primarily through the kicking games of Cleary and Jarome Luai - 1st and 2nd in forced dropouts - the Panthers apply constant pressure to the opposition defence on the goal line and wait for it to crack.

They have scored 44% of their tries down the left edge this season. While their form has been up and down throughout the year, it's still their most reliable option with the ball. A Dally M Team of the Year left edge made up of Viliame Kikau, Matt Burton and Brian To'o caused havoc with their line running and variation. Kikau isn't a crash and bash edge as he was in years gone by. They have developed their attack to use him in different ways and it was his try assist in the Preliminary Final against the Storm that proved the difference.

But as good as Penrith might be down their left edge, they're no Souths.

The Bunnies have scored a whopping 77 tries down their left edge this year which accounts for 55% of their total tries. No team scored more tries anywhere on the field, and no team favoured one side of the field more heavily.

Despite knowing what is coming, opposition defences can't stop South Sydney's left edge attack.

Alex Johnston will finish the year as the NRL's top try-scorer with 29 heading into the Grand Final. Cody Walker's 33 try assists is equal with Johnathan Thurston's premiership-winning season in 2015. Regardless of whether or not Latrell Mitchell is available to add his skillset and gravity to the situation, the Rabbitohs find ways to break down the opposition and cross the line. 

It's no coincidence that these two teams rank 1st and 2nd in yardage either.

Five of the last seven premiership-winning teams have finished inside the top three in running metres per game. Again, the yardage game feels more important than ever under the new rules. Time in possession is crucial with the fatigue in the game. The simplified approach against bottom teams is to hit the advantage line and move the defence around until they tire and crack. Souths and Penrith, along with Melbourne, have succeeded in doing that against the 13 other teams in the competition all season.

Perhaps more important than metres made is metres conceded. Again, like defence and running metres remaining as key components of premiership-winning teams despite the changes in recent years, being towards the top of the list in running metres conceded is also a trend of recent winners. 

Eight of the last ten teams to lift the Provan-Summons Trophy have conceded the fewest or second-fewest running metres throughout the season.

Running metres conceded per game in 2021:

1st: Storm: 1,397 metres
2nd: Rabbitohs: 1,406 metres
3rd: Panthers: 1,485 metres

South Sydney's advantage in this area is especially notable when you consider Penrith's patient approach in attack. While the Panthers do earn 31.6 tackles inside the opposition 20-metre line per game, they only score 0.82 points per tackle which ranks 7th in the NRL. The Rabbitohs, on the other hand, score 1.14 points per tackle across their 27.7 tackles inside the opposition 20-metre line per game - the second-best mark in the competition. 

So, the Panthers have an advantage in defence but it is shrinking the longer the season lasts.

While the Panthers are the better team in yardage with the ball, the Rabbitohs are superior without it.

It's a very long way of saying these two teams are perfectly matched up to produce a ripper of a footy game on Sunday night.

NRL Grand Final Crystal Ball

The Stats Insider Model has simulated the 2021 NRL Grand Final 10,000 times and highlighted the Panthers as premiership winners at a 56% clip. 

These two sides are both at the top of their game defensively. Penrith is one of the best defensive teams in NRL history while Souths have improved more than anybody expected. Still, with the Total set at 38.5 points, the Model has assigned a green smiley to the Over early in Grand Final week. 

It's no surprise to see the Panthers here at this point of the season. It has long been expected that they would reach their second-consecutive Grand Final. However, their path here has been bumpy. Unlike the Rabbitohs, Ivan Cleary's side has been forced to play right the way through September and will be feeling the effects of a long and physical season. The Bunnies, on the other hand, have played just once in the last two weeks and appear to be timing their run to perfection. 

Will the Panthers learn from their 2020 Grand Final experience and go one better, or will Wayne Bennett go out a winner in his 10th appearance in the big dance?

It's not the Grand Final most expected but it's primed to excite.

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