Two outstanding cricketers will appear in their 100th Test match in Perth on Friday. They are the captains of England and Australia, Alastair Cook and Michael Clarke, who will approach this landmark in their sporting lives in different frames of mind but with similar anxieties.
For Clarke, the Ashes urn is so close that he could rip off its top and spray its contents round the dressing room, were that not to be sacrilege, or would be if anybody actually knew what the contents are. But he dare not think of such moments.
Though the evidence of the first two Tests would suggest otherwise, there is still scope, just, for it to slip away from him and his team. In that case, as Clarke is all too aware, Australian cricket would continue to reside in what one of its greatest former players, Adam Gilchrist, described as a world of hurt.
The Ashes Podcast: Stephen Brenkley and Tom Collomosse preview the Third Test. Listen below…
For Cook, whose men have treated the retention of the trophy as if it were nothing more than a cheap terracotta trinket to be tossed about willy-nilly, the concerns are entirely different. He may become one of the few England captains (Percy Chapman, Peter May, David Gower) to have won the Ashes and later lost them. But none of those predecessors surrendered the prize a mere 122 days after winning it.
Somehow, at a venue that has been a house of horrors for England without the relieved laughter at the end of it, he and his men have to find a way of repelling Mitchell Johnson, restoring their nerve and rediscovering their form and belief. They have offered no excuses and there are none for a side who came here as hot favourites and have frozen in the face of the rampant Johnson and his cohorts.
Clarke was in reflective pose as he mused on what lay in store. During the past few weeks there has been a perceptible shift in the way Johnson is viewed by his compatriots. If winning has helped this mood movement, it has been accompanied by the realisation that Clarke was not all they presumed and perhaps by Clarke's recognition of the man he could be.
"I've heard it before," he said. "I've heard throughout this series people say that. I can't really answer it because I don't feel any different. I have said that through my career. I remember a few years ago walking out to a Test match in Brisbane and being booed by my own crowd. Then I go make runs against India or South Africa or whoever it is and people seem to like me more.
"That doesn't mean I have changed as a person, it probably means I have scored a few more runs. I am not doing anything different at all, I am trying to be the best player I can be, I'm trying to help this team be as successful as it can be. My value of playing cricket for Australia has not changed one bit, my love of the game of cricket has not changed one bit."
Clarke was an extremely capable batsman before assuming the captaincy, now he may well be a great one. It has galvanised him: in 31 matches as captain he has scored 12 hundreds, seven fifties and has an average of 63.59, behind only Don Bradman. Clarke provided a semblance of a hint of what might have transpired, no more. "What probably has happened is that the captaincy has allowed the media to get to know me a bit more because I have to do it every second day," he said. "Maybe with the media getting to know me a bit more and in essence the public getting to know me a bit more then that has changed, but that's all."
There are plenty of similarities with Cook. Like Clarke, the England captain is the gilded batsman of his country's cricket. Like Clarke, he made a hundred in his first Test match and the route ahead was clear.
Perhaps it has all come to him so readily – never easily because opening the batting in Test cricket is not easy – but this is not his only hard time. As he recalled: "Anyone who goes back to 2010, that was a really tough time personally in my career and I came out against Pakistan at The Oval and scored a hundred there. This is obviously a tough time and the way you come through it is important."
Now, of course, he is scoring too few runs and he is captain as well. In those circumstances, something eventually has to give. Grim though it is, he has retained a sense of proportion in dealing with setbacks which ought to be helpful to England in adversity.
"I think after day three in Adelaide, it wasn't a particularly pleasant night for me," he said. "I think I've got a good perspective on what cricket is about.
"We are so desperate to put on a good performance and we are very proud of playing for England and the pride and the honour and we haven't played very well and that hurts and hurts like hell. But it is sometimes only a game of cricket and no matter how big it seems at the time it is just a game of cricket and there are other things that can be more important."
Anybody disagreeing with that is a nincompoop. It is why Cook deserves to succeed and just might. And Clarke, the tough operator who threatens Englishmen with broken arms and likes the flash things of life, recalled his first Test against India in Bangalore, to demonstrate how much it all means.
"I remember it like it was yesterday," he said. "I remember Warney presenting me with my baggy green. I remember not picking a wrong'un from Anil Kumble, the ball coming back in and hitting my glove and it shot out to gully. I was batting with Simon Katich and I just ran. Kato looked at me as if to say, 'Are you going to call?' but I just couldn't get the words out so I just kept running and getting off the mark.
"I remember calling for my baggy green on 97, because when I was a young kid sitting in the car with my dad I said to him, 'If I ever get the chance to play cricket for Australia and if I score a hundred, I want to do it wearing that baggy green cap.
"My memories are extremely fond of that day and it is funny because I always heard people saying to me as a young kid how fast time flies when you're playing cricket for Australia and here I am telling young kids the same messages that Warney and McGrath and those guys told me and it is so true." Let their hundredth matches be memorable.
Clarke and Cook: Captains compared
M J Clarke/A N Cook
99 Tests 99
Oct 2004; v India, B'lore Debut Mar 2006; v India, Nagpur
March 2011 Became captain August 2012
7,940 Runs 7,883
26 100s 25
27 50s 33
52.58 Average 47.20
329* Highest score 294
27 Ashes Tests 22
1 Ashes series victories 3
3,243 Runs 1,670
12 100s 7
7 50s 4
63.58 Average 50.60
8 Ashes Tests 7
0 Ashes series victories 1