For more than a quarter of a century, Chicago has been one of the world’s foremost venues for a fast, flat course that also offered pacers. Without the “rabbits” the hope is that the races will be more intrinsically interesting, with the athletes having to rely on their own strategy and tactics.

“We have always tried to blend pace and competition,” Pinkowski told the Chicago Tribune. “But the athletes relied too much on the pace up front, and the chemistry of the competition has become too much about settling in behind the rabbits.

“Without the rabbits, the leaders need a much greater level of concentration. That will allow us to see more tactics, strategy and competition throughout the race.”

Chicago, sponsored by the Bank of America and one of six in the Abbott World Marathon Majors series along with Tokyo, London, Boston, Berlin and New York, will thus be aligning itself with two of that number - Boston and New York.

The race in the Windy City has a tradition of deep elite fields and fast times. Britain’s Steve Jones set a world best of 2:08.05 in 1984, and Khalid Khannouchi won the 1999 race in a world best of 2:05.42 (although, for the last six world records, Berlin has cornered the field).

The women’s race has also produced world best marks, with Kenya’s Catherine Ndereba setting a time of 2:18.47 in 2011, and Paula Radcliffe claiming the record for herself in the Windy City the following year with a time of 2:17.18.

Should a runner break a course or world-record in Chicago, they will still be awarded an additional prize bonus for their efforts.

“This is a place where people always have come to run fast,” Pinkowski added. “Great competition produces great performances.”

Since Pinkowski took over, at least one of the “rabbits” was expected to take the race through to 19 miles at the required pace before dropping out - although in 2001, Ben Kimondiu of Kenya did the last bit too and won.

Kenya's competing runner Wesley Korir, 2012 Boston Marathon champion, recently told Phil Hersh of the Chicago Tribune that the change in mentality by doing away with a pacer could help combat the urge to use banned performance-enhancing drugs in the sport.

"This is one step toward curing the problem," Korir said. "The issue of time, the issue of (trying for) the under two-hour marathon, that is the problem.

"Running 2:03, 2:02, 2:01 is superhuman (the men's world record is 2:02:57). We have very few super humans who can run those times.

"When you have a kid just starting to race, and their mind is already thinking that to make it as a successful runner, you have to run those times, you are forcing them to go overboard, to do something that is not acceptable."

What Hersh terms “the most memorable race in the event’s history” - Joan Benoit Samuelson's win in 1985 - was achieved without pacemakers - and yet she still set a US record that lasted nearly 18 years.

Today, 30 years on from that victory in the memorable time of 2hr 21min 21sec, the athlete who became the first ever Olympic women’s marathon champion on the home ground of Los Angeles in 1984 had hoped to be back at the race in the Windy City - and she had another big target in mind.

However, illness caused her to be a late withdrawal from the event and, as such, she was denied the chance to write another chapter in what has been a memorable career.

At the age of 58, Benoit Samuelson wanted to run within 30 minutes of that US record effort.

“That’s what I’d like to do, but I haven’t said that’s what I’m going to do,” she told WBBM Radio’s Josh Liss recently before the decision to pull out.

“I’ve gone out on a limb, and I don’t normally do this. But running this race is all about the story, and for me that story is to run within 30 minutes of my time of 30 years ago.

“That means 2.51 - and that’s darn fast for me. So we’ll see. It’s perhaps the most challenging goal I have set for myself.”

It would have been challenging, but not unattainable. Samuelson, who had reportedly been training hard, has already recorded 2:54.03 this year in the Boston Marathon.

Samuelson explained that she had thought her final marathon would have been at the 2008 Olympic trials, held in Boston, where she had started her marathon career in 1979.

“I had a goal of running a sub 2:50 at the age of 50, and I accomplished that by the skin of my teeth,” she recalled. “I was greeted at the finish line by all the qualifiers, including Deena [Kastor].

“I walked away having had a great career in the sport and having achieved what I thought was my final goal.”

But, as the late, great US baseball legend Yogi Berra once, memorably, said: “It ain’t over ‘til it’s over.” Samuelson, no doublt, will soon be looking for another opportunity to show what extraordinary levels of performance she is still capable of.

When Samuelson approached the Olympic Stadium in 1984, clear of three legendary figures of the sport in Grete Waitz, Rosa Mota and Ingrid Kristiansen, she was aware of the deep significance of the moment.

“When I came to the tunnel in 1984 I said to myself 'are you capable of coming through this tunnel and carrying the mantle that will come with the first Olympic victory?’

"I can only say I have given it my best shot.”

All six premier marathons are taking a tough line on doping abuse in the wake of high profile cases involving, among others, Rita Jeptoo of Kenya, the Chicago winner of 2013 and, until she was stripped of the title, 2014.

In response, Samuelson said: “I really think of running as a pure sport. I always conducted myself in that space with the highest ethic. I always tell people you have to run your own race. What other races people decide to run are really no business of mine. I just have to be true to myself and do the best I can with my God-given gift.

“It’s too bad that we have all this happening in our sport. I don’t think it’s always been there, and I always say a person is not guilty until proven so. But it is too bad we are dealing with it, it bothers me terribly that it has affected my sport now.”

As one might expect, the notion of a race with pacers did not faze Samuelson for a second.

“I think: ‘pure race, pure sport’, she said. “I was in Los Angeles in 1984 on the right day at the right time. If I had started that marathon a day earlier, or a day later, a week earlier or a week later, the result could have been totally different. It’s all about being on form when it counts.

"I took a lot of grief in Los Angeles because I opted not to take water on the first water stop. The commentators thought I’d made a grave error. Fortunately I couldn’t hear their comments while I was on the road! But you have to run your own race. You cannot run to the beat of anyone else’s drum.

“If you follow a pacer, you are not necessarily running your own race. Every runner, whether they are elite or a first time marathoner needs to really run the race they are capable of.

“The marathon is really a metaphor for life. No matter what your background is, you are going to be challenged along the way. But there are always people there to pull you along.”

Samuelson was quick to correct the idea that she is still the fastest US woman to have run Chicago.

“No I“m not,” she said. “Deena Kastor is that person, a good friend. And she will be back to run as well.”

Kastor, the 2005 Chicago Marathon champion, Olympic bronze medallist of 2004 and American record-holder, will attempt to break Colleen De Reuck’s American masters record of 2:28:40, set in 2005 in Chicago.

The 42-year-old had an impressive 2014 where she set five masters world records en route to her half marathon masters world record of 1:09:37. She is the only US woman in history to have broken the 2:20 barrier.

But Kastor looks like having serious opposition in the form of 40-year-old Blake Russell, who turned 40 in July and has spoken about “chasing a PR” in her blog. As her best is 2:29.10, set in Chicago ten years ago, that could see her in the record zone.

Russell announced her comeback with a win at the 2015 USATF National Marathon Championships in Los Angeles in 2:34:57.

The two women were both on the 2008 Olympic marathon team - and now they meet again. Kastor most recently tied the masters U.S. and world five kilometre record of 15:48, while Russell placed fifth at the USA Track & Field 20km championships in New Haven with 1:08:59.

Samuelson's own perspective on the event which made her famous has altered over the years, and despite the disappointment of missing out today she shows no signs of slowing down.

“Some years ago I did a campaign with Nike with the tag “There’s no finish line.” I didn’t really understand what the campaign was all about. But many years later I am still living that adage.

 “Setting goals is important in anybody’s life, no matter what line of work they are involved with.

“For me now, it is all about the stories. Story-telling is what really motivates me today.

“Marathon runners really have the most inspiring stories. Every person has a story to tell. They should tell those stories because they never know who they might inspire.”

Joe Antonini is, definitively, one such runner.

He signed up to run the first Chicago Marathon 38 years ago, inspired by another running story - that of Pheidippides, credited with running the first “marathon” in 490BC when he ran the 26 miles between the battlefield at Marathon to Athens, carrying news of the Greek victory over the Persian landing force, before collapsing and dying.

As he told Kelly Bauer of DNAinfo, Antonini heard the legend while he was growing up in Italy and was intrigued to take up the challenge of running the distance now fixed for competition purposes at 26 miles and 385 yards.

Antonini is now 75 - and one of only seven men who have run and finished the Chicago Marathon every year since its inception. His best time was 3 hours and 35 minutes “in 1983 or '84”.

Naturally enough, he is down to run again this weekend.

"I love to run it once a year," Antonini said.

"Everything feels great…in the beginning! But despite the aches and pains in knees and hips, I keep coming back.”

Antonini, who is also a part-time soccer referee, lives only a couple of miles from the start in Little Italy. He now drives to the start however - in order to avoid a painful walk home.

His advice to older people contemplating running the marathon is inspirational in itself: “Think twice before you do it. But then do it.”