All summer long the world has been waiting for the battle of the champion speed merchants: Usain Bolt, the Olympic champion and world-record holder in the 100 metres against Tyson Gay, the world champion and fastest man of 2009, in the blue riband event of track and field.
There have been many forecasts as to how long the contest might last. The popular money has been on something less than the 9.69 seconds it took the Lightning Bolt to strike Olympic gold in world-record time in Beijing 12 months ago.
Back then in the Bird's Nest arena on that steamy Saturday evening, the Jamaican took his foot off the gas with 25m remaining. This time, with someone to push him all the way, surely Bolt will take the human speed barrier to yet another limit. We shall see at a little after 8.35pm British time tomorrow – provided, that is, Bolt and his American rival manage to get through the earlier rounds at the world championships without any unexpected mishaps.
It would just take the one false-start to put a dampener on the most anticipated sprint contest since Ben Johnson, pumped up to the eyeballs on Stanozolol, beat Carl Lewis in the Olympic 100m final in Seoul in 1988. Then again, there could be a more literal raining on the high-speed parade. While all of the track and field forecasting has been of a world-record time, the meteorological predictions have been pointing to heavy rain in the west of Berlin tomorrow evening.
How much a downpour might dilute the potency of Bolt or Gay, who last month in Rome equalled his American record of 9.77sec, remains to be seen. At least a little precipitation would add to the historical resonance of the occasion.
Gay, like the rest of the United States team, will be wearing a vest with the initials JO embroidered on to it. It was in a US vest – or "uniform," as the Americans prefer to call it – that Jesse Owens claimed his four Olympic gold medals in the Olympiastadion arena in 1936. He sped to the first of them, in the 100m final, on a heavily rain-soaked track.
Owens was 22 at the time. Tomorrow Bolt will be five days short of his 23rd birthday. Not that he is out to emulate the legend created at the Berlin Olympics 73 years ago. "Not really," Bolt said. "I know he did great things in the stadium here. He was a great athlete. I'll just be focussed on my race and what I have to do. I can't worry about what athletes did in their time. It's my time now."
In truth, Owens' best time as an athlete came not on the Olympic stage in Berlin but on the American collegiate circuit at Ann Arbor, Michigan, in May 1935. Within the space of 45 minutes the Ohio State student equalled the 100 yards world record and set outright world records in the long jump, 220 yards and 220 yards hurdles.
There were four days in between Bolt's 100m world record and his even more spectacular 200m world record of 19.30sec in Beijing. We shall see over the next nine days whether he can measure up to the challenge of producing a follow-up show in Berlin.
The encouraging thing is that he has breezed through the build-up as airily as he did through all of the fuss surrounding him in Beijing. Asked at his razzmatazz press conference about expectations of eclipsing his deeds in the Chinese capital, Bolt said: "I think it's going to be even harder here, but I'm ready. I know what I did last year and I know the responsibility that comes with it. I'm just working hard to do a bit better this year. I just put the work in and I believe in my ability."
And that ability could well take the 100m world record under 9.69sec tomorrow night – Berlin weather permitting.
The main events: Times and TV
Women's heptathlon: from 10.20am (Jessica Ennis)
Men's 100m final 8.35pm (Dwain Chambers, Simeon Williamson)
*Tuesday 18 August
Men's triple jump final 5.05pm (Phillips Idowu)
Women's 400m final 6.35pm (Christine Ohuruogu)
*Sunday 23 August
Women's marathon 10.15am
Men's 4x400m final 5.15pm (Bingham, Clarke, Levine, Rooney, Tobin, Williams)
All can be seen on BBC2/BBC HD