The 2017 IAAF World Championships are right around the corner! Check out the breakdown of the men's 200m and 400m

Men's 200m

When:
August 7, 12:30 PM CT (heats)
August 9, 2:55 PM CT (semi-finals)
August 10, 3:50 PM CT (final)

Top International Contenders: Wayde van Niekerk (South Africa), Isaac Makwala (Botswana), Akani Simbine (South Africa), Yohan Blake (Jamaica), Nethaneel Mitchell-Blake (UK)

Team USA: Ameer Webb, Kyrie King, Isiah Young

2016 Olympic 200m Final:

PLACE	ATHLETE	COUNTRY	TIME	BACK IN 2017?
1	Usain Bolt	JAM	19.78	NO
2	Andre De Grasse	CAN	20.02	NO
3	Christophe Lemaitre	FRA	20.12	YES
4	Adam Gemili	GBR	20.12	NO
5	Churandy Martina	NED	20.13	YES
6	LaShawn Merritt	USA	20.19	NO
7	Alonso Edward	PAN	20.23	TBA
8	Ramil Guliyev	TUR	20.43	TBA

*TBA - athlete's federation has not yet announced official roster for London

Men's 400m

When:
August 5, 4:45 PM CT (heats)
August 6, 1:40 PM CT (semi-finals)
August 8, 3:50 PM CT (final)

Top International Contenders: Wayde van Niekerk (South Africa), Isaac Makwala (Botswana), Baboloki Thebe (Botswana), Steven Gardiner (Bahamas)

Team USA: LaShawn Merritt, Fred Kerley, Gil Roberts, Wil London

2016 Olympic 400m Final:

PLACE	ATHLETE	COUNTRY	TIME	BACK IN 2017?
1	Wayde van Niekerk	RSA	43.03	YES
2	Kirani James	GRN	43.76	NO
3	LaShawn Merritt	USA	43.85	YES
4	Machel Cedenio	TTO	44.01	YES
5	Karabo Sibanda	BOT	44.25	TBA
6	Ali Khamis Abbas	BRN	44.36	NO
7	Bralon Taplin	GRN	44.45	TBA
8	Matthew Hudson-Smith	GBR	44.61	YES

*TBA - athlete's federation has not yet announced official roster for London

8/2 Update: Andre De Grasse has withdrawn from the World Championships due to injury

Analysis: 2017 marks the first senior level global championships in which world record holder Usain Bolt will not contest the 200m since 2003, when, as a seventeen-year-old, he won the World U18 Championships in the event. Bolt's impending retirement after the London World Championships was bound to change the game, but his decision to bypass the 200m entirely to focus on the 100m hastens the changing of the guard. And who better to take up the mantle than South Africa's Wayde van Niekerk?

Last summer, van Niekerk became one of the biggest stars of the Rio Olympics by smashing Michael Johnson's world record for 400m in 43.03 from lane eight. He now hopes to equal Johnson in another measure by becoming the second man in history to sweep the 200m and 400m titles at the World Championships.

Johnson accomplished the difficult feat at the 1995 World Championships and 1996 Olympic Games. Two women have pulled off the rare 200m/400m double: Valerie Brisco-Hooks of the United States at the 1984 Olympic Games and Marie-Josée Perec of France at the 1996 Games.

Van Niekerk's world record holder status should make him untouchable in the longer event, though NCAA fans will be thrilled at the prospect of a race against the seemingly fearless Fred Kerley, whose 43.70 broke Quincy Watts' 25-year-old collegiate record and ranks No. 6 in American history and No. 7 in world history. van Niekerk's season-best is 43.62.

van Niekerk's fellow Rio medalists may not pose a challenge at all, as Grenadian silver medalist Kirani James will not race due to injury and American LaShawn Merritt, the Rio bronze medalist, has not looked in form this season. He earned a 'bye' to the Championships by virtue of his status as the 2016 Diamond League champion, but his season best of 44.78 ranks just No. 17 in the world this year and he hasn't raced since making a requisite jog through the 200m prelims at the U.S. Championships.

The rest of the American contingent includes Gil Roberts, who ran on the gold medalist 4x400m relay in Rio last year, and Wil London, a Baylor sophomore who delivered one of the most surprising performances of the U.S. Championships to make his first senior world team.

It's possible that someone besides van Niekerk pulls off the double, as breakout star Isaac Makwala of Botswana poses the top threat in both events after posting a ridiculous 43.92/19.77 double at the Madrid World Challenge earlier this month. Makwala raced van Niekerk over 400m less than a week later at the Monaco Diamond League meeting and made the 25-year-old work for the win: 43.73 to 43.84. The 30-year-old Makwala's 200m time displaced van Niekerk at the top of the world list this year and certainly looks capable of spoiling his plans to double.



The 200m will be much tougher for van Niekerk to win as Rio silver medalist Andre De Grasse of Canada returns, as does bronze medalist Christophe Lemaitre of France. De Grasse is undefeated over 200m this season, including wins at the Rome and Rabat Diamond League meetings over the likes of Lemaitre and U.S. champion Ameer Webb. His wind-legal best of 20.01 ranks No. 8 in the world this year, though many ahead of him will not compete in London, including Americans Christian Coleman, Noah Lyles, and Christopher Belcher.

Of the American contingent, neither Webb, a 2016 Olympian, nor Isiah Young, a 2012 Olympian, has ever made a global championship final. London will be the first senior level championship for Kyree King, a recent graduate of the University of Oregon, who is having a dream season to make Team USA after placing just fourth at NCAAs.