Two Springbok packs can't match the tempo of Ireland's one

The mythology of the Springboks bench grew more than an arm and a leg following the destruction of the All Blacks at Twickenham.

Such was made about the power-packed forward replacements that many have forgotten to look at the team sheets.

The 7-man All Black pack was full of young talent in the second half with Tamaiti Williams and Fletcher Newell barely putting together 10 caps between them. Newell, coming back from a six month foot injury, had been called upon in the 13th minute.

Josh Lord and Tupou Vaa'i anchored the second row, just 22-years-old and 23-years-old respectively.

This was boys against men in relative terms and the boys had one less to play with, calling on second five-eighth Jordie Barrett to pack down at scrum time.

But of course the context doesn't matter and all of a sudden the 7-1 split is now the greatest thing in rugby and Ireland should be quivering at the thought of it because they beat up the All Blacks' kids.

Unless Ireland get an early red card up front and have a bench full of developing players, then they will be just fine.

The two pack strategy is going to be less effective this time around, purely due to the losses South Africa have suffered.

Losing Malcolm Marx, the world's best hooker and one of the strongest forces over the ball in the game, massively weakens the impact of this ploy.

Whether in the starting side or coming off the bench, Marx is a game-changer whose impact cannot be replaced.

More baffling is that they have replaced him with a loose forward in Deon Fourie.

That Fourie has played 15 games as a rake out of 127 club games does not make him a Test quality hooker. This bit part No 2 last played a game there in 2017 and most of his playing experience at the position was 10 years ago.

Even hookers struggle to play hooker at Test level, such are the small margins for error. The selection of a career loosie smells of over-confidence that has the potential to backfire spectacularly.

It's one thing to train at hooker it is another thing entirely to play hooker against the world's number one team in the Test arena.

Duane Vermeulen has been in resurgent form this year, proving to be a handful off the bench against the All Blacks in Auckland earlier this season.

Ireland will be happy to see Jasper Wiese in his place instead, a wildcard No 8 who has habitually cost the Boks with discipline issues. Kwagga Smith is a powerful ball carrier but Ireland will feel they can handle his 1.80 metre frame.

Both Wiese and Smith were below par against the All Blacks at Mt Smart, leading to questions about the strength of the Springboks backrow in the aftermath.

When it boils down to it, this bench is not on the same level as the starting pack and the losses of Marx and Vermeulen are huge.

Although the bench brings fresh legs, injecting new players is a disruption that can ruin momentum. If Fourie can't hit the timing on his throws, it doesn't matter how powerful the maul is.

Often when new front rowers come on teams find their fortunes change at scrum time. So many teams can lose set-piece ascendency as fresh players get themselves into the game.

And of course, all it takes is one early injury in the backline outside of scrumhalf to completely derail this bench.

It looks like genius when it works but the day it is exposed, the foolishness will be apparent. That day will come sooner or later.

Ireland's forwards will not be bothered in the slightest and all the talk about how formidable the Springboks' two packs are will only put more fire in the belly.

The Irish pack play at a speed and tempo that the Springboks can't match at full speed.

Tadhg Beirne, Caelan Doris, James Ryan, Peter O'Mahony, and Josh van der Flier clear more bodies than a morgue.

The famed Irish missile cleanouts will be pummelling the backs of white jerseys with a little extra oomph and Jamison-Park will be clearing ball fast.

Tempo will decide this game and if Ireland reach theirs, the Boks' massive bench will turn into a massive liability.

If South Africa can't slow the ball down their two packs are going to be fodder for the green machine.