Those with a glass half empty perspective are quick to point out that Ireland are getting perilously close to that famous definition of insanity.

It all sounds a bit familiar.

There are more than enough differences between the current side and the one of November 2017 to suggest that history is not destined to repeat itself. Ireland are world number ones, but firm in their belief that they are not yet close to their peak.

One area they can point to as a sign of growth at this stage of the World Cup cycle is depth and competition for places.

With France 2023 coming into view there are a lot of spots, both in the starting side and on the plane, very much up for grabs.

With that in mind, which players need to make a statement in the autumn Tests against South Africa, Fiji and Australia?

Robert Baloucoune

Watching him in full flight, it is easy to see why conversations on Robert Baloucoune tend to centre around his staggering top speed.

It is his point of difference. The weapon in his arsenal that even among elite competition gives him an edge that few others in professional rugby possess.

But Baloucoune is determined to build a reputation based on far more than pace. The Enniskillen man sees defensive solidity and rugby IQ as the cornerstones of his game.

Injuries to James Lowe, Andrew Conway, and Keith Earls opened the door for Baloucoune to start against the Springboks, and Saturday's game will be a huge test of his World Cup credentials.

His most recent start came 12 months ago against Argentina, when he was too often a peripheral figure in a game that was comfortably won up front.

The message from the Irish coaches to Baloucoune came loud and clear on the recent Emerging Ireland tour: come off your wing and get involved.

They recognise in the 25-year-old a player with the ability to break any game wide open. They need him on the ball.

Conor Murray

You might argue that a man on the eve of his 100th international cap has little to prove in the Test arena.

Saturday's landmark will only further cement Conor Murray's standing in Irish rugby, and yet a year out from the World Cup he could do with a statement performance.

Having not played a minute since that win in Wellington three-and-a-half months ago, Andy Farrell deemed that sending Jamison Gibson-Park straight in against the world champions would be a tough ask.

But make no mistake, Gibson-Park remains the number one choice at scrum-half. It would take either an injury or his form falling off an improbable cliff for him not to be on the plane to France.

That leaves 33-year-old Murray vying with highly rated youngsters Craig Casey and Nathan Doak for the back-up spot, possibly all competing for just one space if we're going by the make-up of the 2019 squad.

This weekend's selection tells us that Murray's safe hands are still Farrell's preferred choice when Gibson-Park is not 100%. But with Casey and Doak both now involved in the international set-up, Murray can ill-afford a poor performance.

Dan Sheehan

Everyone with an interest in Irish rugby is crossing everything that Ronan Kelleher's recent run of injuries are a blip and not a pattern.

Kelleher's emergence at such a young age was a major boost for Ireland. They had someone who could, if he reached his potential, hold down the hooker role for the best part of a decade.

Then when Dan Sheehan came onto the scene, Ireland were in dreamland.

With just eight months between the two 24-year-olds in age Ireland were, and still are, looking at the prospect of two world-class hookers with their best years in front of them bringing out the best in each other as they compete for the starting jersey.

By the time he injured his shoulder against France in the Six Nations, Kelleher had edged ahead. His absence saw Sheehan take over, and after a difficult day in the scrum on his first Six Nations start against England, he has gone from strength to strength.

Excellent against the All Blacks, Sheehan now looks every inch the real deal. Another solid international window will make the number two jersey his to lose.

Stuart McCloskey

It now seems to be generally agreed that Stuart McCloskey has been a far more consistently high class performer than his six international caps would suggest.

Up to this point he has been a victim of circumstance. While Robbie Henshaw, Garry Ringrose and Bundee Aki rarely seem to be fit at the same time, two of the three usually tend to be.

They are three of the best centres in rugby, not just Ireland. Their consistent excellence has kept McCloskey out of the team despite his own sustained period of high quality performances.

The nickname 'the Bangor bulldozer' is as misleading as it is unfair on McCloskey. Similar to Baloucoune, you look at his stature - 6ft 4in and 17st plus - and think you have a good read on what type of player you are getting.

But McCloskey, 30, is not a crash ball specialist. He possesses a sleight of hand and playmaking ability that are the envy of most European centres.

He is on the bench against the Springboks but will hope for a start in one of the other two autumn games as he seeks to upset to established midfield pecking order.