Usain Bolt: Can the legend sign off with London 2017 World Championships win?

Slower, later, weaker.
For a man who has lived the Olympic ideal of faster, higher, stronger, they are strange words to attach to Usain Bolt.
His fastest 100m time so far this year is 9.95 seconds.
At the same stage last year – in the build-up to the Rio Olympics – he had run 9.88.
Before the World Championships in Beijing in 2015, he had clocked 9.87.
Heading into Moscow 2013, his best was 9.85. Before London 2012, it was 9.76.
Each time, he improved to win gold, but in progressively slower times as the years advanced.
That 9.58-second scorched-earth world record from Berlin 2009 belongs to the same man, but a different, irrevocable era.
Bolt, now 30, comes into this London edition of the World Championships, not as a sensation heralding a revolution, but instead hanging onto his empire against the challenge of Father Time and young pretenders.
With three rounds of the 100m, roughly 30 seconds of action, left of his career, could Bolt, weighed down with 19 World and Olympic gold medals, possibly bow out in defeat?
Bolt may never have been slower before a major championship, but the threats to him have rarely been less clear.
The fastest man this year is Christian Coleman.
The American’s best of 9.82 seconds was one of six occasions on which he dipped under 10 seconds this season.
Just 21, Coleman’s expanding portfolio of performances attracted a seven-figure sponsorship deal from Nike as the sportswear giant made him their bet as Bolt’s long-term successor.
He told the Daily Telegraph that he was “pretty much a deer in the highlights” at the Rio Olympics where he appeared in the heats of the 4x100m relay.
The final of the United States trials – the biggest race of his season – delivered only his fifth-fastest time of the year and second place.
Bolt’s old sparring partner Justin Gatlin was the man who beat Coleman.
The 35-year-old claims he feels back to his 100m heyday when he won Olympic and world titles in 2004 and 2005, a time predating both Bolt’s emergence and his own two doping bans.
He has only beaten Bolt once in his long career – at a Diamond League meeting in Rome in 2013.
By contrast in major finals in 2012, 2013, 2016 and most notably at the world championships in Beijing 2015 when Gatlin came into the final faster and favoured, he was left in the Jamaican great’s wake.
Yohan Blake is the second fastest man in the world this year – and of all time, behind Bolt.
He profited when Bolt fouled out of the 2011 World Championships and did the 100m-200m double in his compatriot’s absence in the Jamaican trials this year.
But the 27-year-old has been hindered by a run of injuries in recent seasons and pulled out of the Diamond League meeting in Rabat in mid-July with a groin problem.
If Nike plumped for Coleman, Puma – Usain Bolt’s own shoe sponsor – signed up Andre de Grasse in a multi-year, multi-million deal in 2015 as their pick for the next 100m superstar.
It seemed a good choice when the Canadian won bronze in Rio last summer. Less so this season however, where he has been only the 23rd fastest in the world.
Former 1500m world champion and BBC Sport commentator Steve Cram has stated that Usain Bolt would not have given this field a second thought two or three years ago. He is not as good as he was. But he doesn’t have to be.
Cram added that from whatever we have seen so far, he believes Bolt would be better in London.