Three years ago, as Katarina Johnson-Thompson took European Indoor Championships gold, Nafissatou Thiam was little more than a footnote.

Thiam - then 20 - was second in Prague, but never seriously threatened to halt Johnson-Thompson's advance on the top prize.

After securing victory, Johnson-Thompson was more disappointed by missing out on the pentathlon world record than concerned by the threat of the Belgian student wearing silver on the step below.

A new world order has been ushered in since then.

Thiam is now Olympic and world heptathlon champion. She is one of only four women to surpass 7,000 points in the event. At the end of 2017, she was voted as the world's outstanding female athlete.

Thiam (left) and Johnson-Thompson (centre), with Czech bronze medallist Eliska Klucinova, at the 2015 European Indoor Championships in Prague

With Germany's Carolin Schafer and the Netherlands' Anouk Vetter - world silver and bronze medallists respectively - in the field at the European Championships in Berlin, Johnson-Thompson, 25, faces a fight to even make the podium when the heptathlon competition begins on Thursday.

Like the rest, Johnson-Thompson, long heralded as the "golden girl" of British athletics, is now measured against Thiam's gold standard.

Toni Minichiello, who coached Dame Jessica Ennis-Hill to world and Olympic triumphs, says this largely unexpected turnaround comes partly from Thiam's unconventional development as a multi-eventer.

"Usually the improvement comes in the throws while the jumps are more natural and the sprint speed develops over time," he told BBC Sport.

"Thiam has been vice-versa. She came in with very good throws and has developed in other areas instead. She has broken the mould in that sense.

"She has always had a couple of events that are absolute monsters where she really cashes in big points.

"Now she is also a very competent long jumper and sprint hurdler. She may lose a bit in the 200m and 800m, but she more than makes up for that with a 1.90m-plus high jump, 50m-plus javelin and 15m-plus shot put."

So how does Johnson-Thompson compare in a discipline-by-discipline breakdown?

100m hurdles

Back in 2012, Johnson-Thompson was nearly a second quicker than Thiam in heptathlon's opening event. Now, Thiam's gradual improvement means the difference between the pair is negligible.

"Katarina is the slightly better hurdler, but not by much anymore," said Minichiello.

"She doesn't get the same points head start that she once did. That advantage no longer exists."

High jump

This was the event that cost Johnson-Thompson at London 2017. Her failure to clear higher than 1.80m left her irrevocably off the pace in the heptathlon.

Six days later, she showed something closer to her best form as she cleared 1.95m to finish fifth in the individual event.

But Thiam reached new heights this year, breaking the two-metre barrier for the first time with a leap of 2.01m at the Gotzis meeting in Austria.

"They both jumped 1.98m in Rio 2016, but Katarina is not in that sort of form this season with a best of 1.91m outdoors," said Minichiello.

"Thiam can take maybe 70-odd points (equivalent to roughly 6cm better) out of Johnson-Thompson here and eat up any ground she has lost in the hurdles.

"A jump of 1.92m to 1.95m has to be minimum for Kat to stay in the game and limit the damage."

Shot put

Another discipline where the two are apparently going in opposite directions.

While Thiam has added 5cm to her outdoor personal best this season, Johnson-Thompson has not broken 13m since 2016.

"This is an erratic - and potentially very costly - event for Johnson-Thompson," said Minichiello.

"Three metres, which could easily be the difference between the pair, is worth 200 points."

200m

Thiam clocked 25.10 seconds in the 200m at Rio 2016 and still had enough in the rest of her programme to sensationally defeat defending Olympic champion Ennis-Hill.

Johnson-Thompson's training base is in the French city of Montpellier, where she works in the same group as Frenchman Kevin Mayer, the Olympic decathlon silver medallist

She has improved significantly since then. Johnson-Thompson is better, but has not strengthened this event since switching her training base from Liverpool to France after Rio 2016.

"Thiam has improved her score by another 50 points since 2016 by getting down to the mid-24s," said Minichiello.

"Katarina has been a 22-second 200m runner for five seasons now.

"This is an opportunity to earn 100-150 points back on Thiam. She has to maximise this chance by putting some distance between her and Thiam."

Long jump

Johnson-Thompson's jump of 6.93m back in 2015 at the Birmingham Grand Prix set a new indoor British record, but she has struggled to replicate it when multi-eventing.

 

In the World Championships later that year in Beijing, she fouled out without registering a jump.

Thiam continued her steady progression by eking another 5cm extra out of her personal best in Gotzis in May.

"Johnson-Thompson jumped 6.70m at the Anniversary Games in July, but that, once again, was when she was fresh," said Minichiello.

"It has not been the kind of distance that she is jumping after day one of a heptathlon competition. It is the fifth event and fatigue plays a part.

"Having said that, following on from the 200m, it is another chance for her to take some points out of Thiam and turn the screw."

Javelin

Thiam is unmatched as the best javelin thrower in Belgian history. She has registered distances in excess of 50m since she was a teenager.

There are some more demons lurking in this event for Johnson-Thompson, who saw her Rio 2016 campaign flounder with a best effort of 36.36m.

"Don't' be fooled by Thiam's throw of 47.20m in Gotzis this year," said Minichiello.

"The difficulty with Gotzis - an Austrian alpine town - is the wind coming off the mountains.

"In 2017 the wind was behind the field and they all threw very far, with Thiam registering her personal best of 59.32m.

"This time there was a strong crosswind that dragged the javelin down. In the shelter of the Olympic Stadium in Berlin it will be a different result.

"Katarina only threw 39.98 at the British Championships and I think it will be about a 10m difference - which equates to about 200 points."

800m

The final event and, with athletes able to work out what they need to do to gain or protect a medal, the 800m can become very tactical.

"Personal bests can be a little misleading here as heptathletes run to necessity rather than their maximum," said Minichiello.

"Thiam didn't run as fast as she could have in the 800m in London because there was no necessity to do it. She produced 2.21, but is capable of 2.15.

"KJT has latched onto other people in the past and, if someone paces it for her, she is capable of running seven or eight seconds quicker than Thiam.

"A seven-second difference is worth just over 100 points."

Heptathlon

By then though, Thiam may well be out of sight.

"Katarina needs to improve her mentality and consistency, but the big thing is that her throws are not strong enough to compete with Thiam," said Minichiello.

"The gap that Katarina builds up in her big events - hurdles and 200m - is not enough to negate Thiam's javelin, shot and high jump.

"Because of the way the points system works, those sprint events don't give you the same opportunity for landslide points wins over your rivals.

"It is a hard thing for Katarina to overcome."