For the hundreds of world-class athletes who made the journey to Poland for the World Athletics Relays Silesia 21, this hasn&rsquo;t been a straightforward task, and the same goes for all those who have worked tirelessly to make the event possible.
On the eve of the competition on Friday (30), there was agreement among those at the press conference that the effort has been worthwhile.
&ldquo;Our journey was a bit tricky, we travelled for close to 30 hours but we&rsquo;re grateful we&rsquo;re able to compete,&rdquo; said Akani Simbine, who will run the 4x100m for South Africa. &ldquo;It&rsquo;s been a priority for us to get here and get here in the best shape.&rdquo;
Although South Africa has already secured Olympic qualification in the men&rsquo;s 4x100m, Simbine highlighted why it was so important to be present given his nation was just 0.3 away from a medal when finishing fifth at the 2019 World Athletics Championships in Doha.
&ldquo;We&rsquo;re a country that believes in ourselves and the talent that we have," he added. "We&rsquo;ve been trying to get the team together and make sure we&rsquo;re ready to compete once we get to Tokyo. That for us is going to be an important chance to do something great for our country.&rdquo;
World Athletics President Sebastian Coe acknowledged the difficulties facing so many athletes around the world but highlighted why it was so important this event made it to the start line.
&ldquo;It would have been easier to cancel, we recognise that,&rdquo; he said. &ldquo;We recognise the world we live in at the moment, but what we&rsquo;ve tried to do is provide an event that gives athletes as good a chance as possible to qualify (for major championships) and to get competition under their belts. It&rsquo;s absolutely imperative we maintain competitive structures as long as we can.&rdquo;
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For Dutch star Femke Bol, this will be her second appearance at the World Athletics Relays, having made her debut in Yokohama in 2019 at the age of 19. The European indoor 400m champion ran a blazing 49.99 &ndash; the third fastest indoor split in history &ndash; to help the Netherlands to gold in the women&rsquo;s 4x400m in Torun back in March and in her first competition since, she feels her long, raking stride will be even more effective on an outdoor track.
&ldquo;I&rsquo;m feeling fit and ready to run,&rdquo; she said. &ldquo;Outdoors is different and I don&rsquo;t have difficulty with small bends so I&rsquo;m ready to show what I got.&rdquo;
Bol is listed on the Dutch squads for both the women&rsquo;s 4x400m and the mixed 4x400m, with a decision due on her exact competitive schedule after a team meeting on Friday, and she&rsquo;s looking forward to returning to action alongside some training partners from the Olympic Training Centre in Papendal.
&ldquo;I think relays have become more important in the Netherlands and everyone wants to be a part of the team,&rdquo; she said. &ldquo;You run individual but, together, you achieve more. We got one week off (after the indoor season) and then trained hard again. We did really hard sessions and our entire team is ready to compete.&rdquo;
Another returning to action for the first time since the European Indoor Championships is Poland&rsquo;s Joanna Jozwik, who won 800m silver behind Britain&rsquo;s Keely Hodgkinson in Torun in early March. Silesia holds a special place in Jozwik&rsquo;s heart, given it is where she spent much of her time rehabbing from injury in the years after finishing fifth in the 2016 Olympic 800m final in Rio.
&ldquo;It&rsquo;s here in Silesia I found a doctor who helped me recover and it&rsquo;s here I spent a lot of time regaining fitness,&rdquo; she said. &ldquo;I hope it&rsquo;ll never again happen to me. The path has been long and hard at times, it took a lot of mental work and physical work. I&rsquo;m overwhelmed with joy that Silesia can organise such a great event and I&rsquo;m very proud, very humbled and confident we will do very well.&rdquo;
At the Silesian Stadium in Chorzow this weekend, she will contest the 2x2x400m alongside Patryk Dobek, the European indoor men&rsquo;s 800m champion. She believes Dobek can break 50 seconds for both of his legs but she remained tight-lipped when asked about her own intended target.
&ldquo;Honestly, I&rsquo;m very excited,&rdquo; she said. &ldquo;This resembles tempo training but with an extreme short break. It&rsquo;ll be a challenge but wonderful to watch.&rdquo;
<img src="https://assets.aws.worldathletics.org/608bffd8720d89f413d0ade7.jpg" alt="" width="950" height="635" />World Athletics President Sebastian Coe and Marshal of the Silesian Voivodeship Jakub Chelstowski&nbsp;(&copy; Krzysztof Wesolowski / LOC)
 Jakub Chelstowski, Marshal of the Silesian Voivodeship, beamed with pride as he welcomed the trio of world-class athletes to the event.
&ldquo;This is our dreams coming true, not only my dreams but the dreams of our residents,&rdquo; he said. &ldquo;We were saying from the very beginning, &lsquo;we can do this, we cannot give up,&rsquo; and this demonstrates we are right. Unfortunately we cannot invite the fans, but we&rsquo;re still happy you are with us.&rdquo;
Coe expressed his gratitude to all those who overcame the logistical headaches to ensure the event could go ahead.
&ldquo;The people of Poland, the local authorities, the organising committees, the federation, have done so with a resilience and a fortitude and an innovative approach that we can all learn from,&rdquo; he said. &ldquo;These championships come at a critical moment in the athletics season and we&rsquo;ve done everything we possibly can to maintain as much competition as possible, as safely as possible.&rdquo;
Cathal Dennehy for World Athletics

World Athletics Relays

For the hundreds of world-class athletes who made the journey to Poland for the World Athletics Relays Silesia 21, this hasn’t been a straightforward task, and the same goes for all those who have worked tirelessly to make the event possible.

Painstaking preparations pay off, with athletes ready to put on a show in Silesia

While qualifying for major championships is serious business for most teams competing at the World Athletics Relays Silesia 21, there&rsquo;s still scope for some light-hearted and less-pressured disciplines at the Silesian Stadium on 1-2 May.
Indeed, these non-championship-qualifier disciplines have provided some of the more memorable and surprising moments at the World Relays since the inaugural edition in 2014, and that looks set to continue this year.
The mixed shuttle hurdles relay and mixed 2x2x400m will be held as straight finals on day one, while the men&rsquo;s and women&rsquo;s 4x200m events will be held as straight finals on day two. 
<h2>Men&rsquo;s 4x200m: Germans carry slight edge</h2>
Having finished third in 2015 and 2019, Germany will be aiming for another top-three finish when they line up for the two-lap event.
Their line-up for Silesia, however, is completely different than the quartet that set a national record of 1:21.26 in Yokohama two years ago. Two-time national champion Steven Muller is the fastest member of their squad, but he has limited relay experience.
In terms of pure speed, Ecuador boasts the strongest sprinter of the entire field in the form of world bronze medallist Alex Quinonez. His four teammates &ndash; three of whom are teenagers &ndash; will be hoping the Pan American champion can put the team in the mix.
Kenya has a surprisingly solid record in this event at the World Relays, having placed fourth in 2019 and fifth in 2014. Mark Odhiambo, who featured on Kenya&rsquo;s team in 2017 and 2019, is back for his third World Relays performance and is fresh from a recent 10.11 100m PB.
<img src="https://assets.aws.worldathletics.org/0a01ce75-a2fa-4bf4-b051-2ee0501ca10a.jpg" alt="" width="950" height="635" /> Kenyan sprinter Mark Odhiambo at the 2017 World Relays (&copy; Getty Images)
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Denmark may not have the same depth as some nations, but teenager Tazana Kamanga-Dyrbak &ndash; who recently set a Danish record of 20.48 &ndash; is their secret weapon. Even if they fail to finish in the top three, the national record of 1:25.53 is an achievable target for the Danish quartet.
Hosts Poland, the fourth-place finishers in 2015, has also entered a team, as has Portugal. 
<h2>Women&rsquo;s 4x200m: wide open race with new winner guaranteed</h2>
For the fifth consecutive edition of the World Relays, the women&rsquo;s 4x200m will have a new winner.
All four of the past winners &ndash; USA, Nigeria, Jamaica and France &ndash; haven&rsquo;t entered a women&rsquo;s 4x200m team for Silesia. It should still be a highly competitive race, though.
Ecuador, who set a national record of 1:35.91 to finish sixth in Yokohama two years ago, has entered the same quartet. Bolstered by the likes of multiple world U18 and U20 medallist Angela Tenorio and rising talent Gabriela Anahi Suarez, who ran 11.16 last year as an U20, the Ecuadorian squad has plenty of speed. It&rsquo;s just a question of whether their baton passes can do them justice.
Poland&rsquo;s 2019 European indoor 60m champion Ewa Swoboda and national 200m champion Marlena Gola feature on the host nation&rsquo;s team.
<img src="https://assets.aws.worldathletics.org/ca3a9740-6be6-40d6-9816-088fea2dde13.jpg" alt="" width="950" height="633" /> Mathilde Kramer of Denmark in the women's 4x100m at the World Relays Yokohama 2019 (&copy; Roger Sedres)
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The four women who set a Danish 4x100m record to win their heat at the last World Relays &ndash; Astrid Glenner-Frandsen, Ida Karstoft, Mette Graversgaard and Mathilde Kramer &ndash; have been named in the 4x200m for this year&rsquo;s competition. As is the case with the men&rsquo;s event, the Danish record (1:39.35) appears to be living on borrowed time.
Ireland&rsquo;s sprint depth has been steadily improving in recent years, and some of their rising stars &ndash; including 2017 European U20 champion Gina Akpe-Moses and hurdles specialist Molly Scott &ndash; will be in action in the 4x200m in Silesia. 
<h2>Mixed 2x2x400m: hosts Poland take on the mighty Kenya</h2>
When this discipline made its debut at the 2019 World Relays, it became clear &ndash; roughly when the athletes were half-way through their second lap &ndash; that it suited middle-distance runners more than pure sprinters.
Armed with that knowledge, most countries have entered 800m specialists for Silesia.
Poland has a strong line-up which includes Patryk Dobek, the 400m hurdler who switched to the 800m earlier this year and won the European indoor title in what was his fourth competition at the distance.
He helped Poland to a fourth-place finish in this event two years ago, but with that 800m experience now in his legs, he&rsquo;ll be better equipped for the unique demands of this race. Olympic finalist and European indoor silver medallist Joanna Jozwik is also on the team.
But Kenya has also named a strong line-up for this event, featuring world 800m bronze medallist Ferguson Cheruiyot Rotich, Commonwealth 800m champion Wyclife Kinyamal and 1:58.04 performer Emily Tuei. Just two of those will compete, of course, and the race will all boil down to who has best distributed their energy between their two 400m efforts.
Slovenia, represented by Anita Horvat and Zan Rudolf, should also be in contention. Other entries include Belarus, Portugal and the Slovak Republic. 
<h2>Mixed shuttle hurdles: close contest expected between Germany and Poland</h2>
Just three teams have been entered for this discipline this year, though just two of those carry realistic hopes of winning.
Poland&rsquo;s line-up features national record-holder Artur Noga and multiple national champion Damian Czykier. Klaudia Wojtunik, who clocked a PB of 13.08 last year, is the fastest woman on the team.
Germany, meanwhile, may call upon the vastly experienced duo of Erik Balnuweit and Gregor Traber, placing them alongside European finalist Ricarda Lobe.
Kenya is the third team entered, though their best hopes of relay success in Silesia lie in other events.
One of the newest disciplines on the World Relays programme, the shuttle hurdles relay features two men and two women on each team, running 110m legs. The race begins with the women running their standard 100m hurdles race from the finish line towards the traditional start, but running an extra 10 metres at the end of their leg to account for the extra distance.
They will then change over to the first man on the team who will run the standard 110m back up the straight in the adjacent lane and then change over to the second woman, who in turn will change over the second man who will run the anchor leg.
Jon Mulkeen for World Athletics

While qualifying for major championships is serious business for most teams competing at the World Athletics Relays Silesia 21, there’s still scope for some light-hearted and less-pressured disciplines at the Silesian Stadium on 1-2 May.

Surprises in store in non-qualifier relays in Silesia

A Jamaican team of 39 athletes, including multiple global gold medallists&nbsp;Elaine Thompson-Herah and Asafa Powell, has been selected for the&nbsp;World Athletics Relays Silesia 21&nbsp;on 1-2 May.
Jamaica will be represented in seven events, including the women's and men's 4x100m, 4x200m and 4x400m plus the shuttle hurdles relay.
Thompson-Herah &ndash; who was part of the third-placed 4x200m team at the last edition of the event in Yokohama in 2019 &ndash; has been named for the women's 4x100m and 4x200m squads, while Powell is included in the men's 4x100m team.
Stephenie Ann McPherson, a member of Jamaica's winning 2015 world 4x400m team, has been selected for that event along with her teammate&nbsp;Shericka Jackson, who also claimed 2019 world 4x100m gold.
Nathon Allen, who anchored Jamaica to the runner-up spot in Yokohama three years ago and also has Olympic and world medals to his name, is again in the 4x400m squad.
Commonwealth 110m hurdles champion&nbsp;Ronald Levy is among those named for the shuttle hurdles relay.
<h3>Jamaican&nbsp;team for Silesia</h3>
WOMEN 4x100m:&nbsp;Ramona Burchell,&nbsp;Kashieka Cameron, Shashalee Forbes,&nbsp;Natasha Morrison,&nbsp;Elaine Thompson-Herah,&nbsp;Natalliah Whyte 4x200m:&nbsp;Shashalee Forbes,&nbsp;Tiffany James, Anastasia Le-Roy,&nbsp;Candice McLeod,&nbsp;Elaine Thompson- Herah,&nbsp;Natalliah Whyte 4x400m:&nbsp;Christine Day,&nbsp;Shericka Jackson,&nbsp;Tovea Jenkins,&nbsp;Roniesha McGregor,&nbsp;Stephanie Ann McPherson,&nbsp;Janieve Russell,&nbsp;Shiann Salmon, Rhonda Whyte &nbsp;
MEN 4x100m:&nbsp;Oshane Bailey, Nesta Carter, Nigel Ellis,&nbsp;Julian Forte,&nbsp;Kadrian Goldson,&nbsp;Asafa Powell,&nbsp;Romario Williams 4x200m:&nbsp;Michael Bentley,&nbsp;Nigel Ellis,&nbsp;Kadrian Goldson,&nbsp;Romario Williams 4x400m:&nbsp;Nathon Allen,&nbsp;Zadrian Barnes,&nbsp;Keeno Burrell,&nbsp;Javon Francis, Jamoi Jackson, Demar Murray,&nbsp;Terry Thomas,&nbsp;Troy Whyte
MIXED Shuttle hurdles relay:&nbsp;Rasheed Broadbell, Janeek Brown, Deuce Carter, Ronald Levy, Megan Tapper, Jeanine Williams

A Jamaican team of 39 athletes, including multiple global gold medallists Elaine Thompson-Herah and Asafa Powell, has been selected for the World Athletics Relays Silesia 21 on 1-2 May.

Jamaica selects 39-strong squad for Silesia

Dafne Schippers,&nbsp;Churandy Martina and&nbsp;Femke Bol are among the 24 athletes selected to represent the Netherlands at the&nbsp;World Athletics Relays Silesia21 on 1-2 May.
The squad will compete in the 4x100m and 4x400m events.&nbsp;Dutch teams have already achieved Olympic qualification in the men's 4x100m and women's 4x400m, with the other teams in action at&nbsp;the Silesian Stadium in Chorzow, Poland,&nbsp;also targeting qualification for Tokyo and the World Athletics Championships Oregon22.
Five athletes feature in each 4x100m squad, while eight athletes have been named for the&nbsp;women's 4x400m and six for the men's 4x400m. The mixed 4x400m team will be&nbsp;selected from the athletes within the two 4x400m squads.
<h3>Dutch team for Silesia</h3>
WOMEN 4x100m:&nbsp;Jamile Samuel,&nbsp;Dafne Schippers,&nbsp;Naomi Sedney,&nbsp;Marije van Hunenstijn,&nbsp;Nadine Visser 4x400m:&nbsp;Femke Bol,&nbsp;Andrea Bouma,&nbsp;Laura de Witte,&nbsp;Lisanne de Witte,&nbsp;Marit Dopheide,&nbsp;Eva Hovenkamp,&nbsp;Lieke Klaver,&nbsp;Eveline Saalberg
MEN 4x100m:&nbsp;Taymir Burnet,&nbsp;Christopher Garia,&nbsp;Churandy Martina,&nbsp;Hensley Paulina,&nbsp;Joris van Gool 4x400m:&nbsp;Terrence Agard,&nbsp;Ramsey Angela,&nbsp;Liemarvin Bonevacia,&nbsp;Jochem Dobber,&nbsp;Tony van Diepen,&nbsp;Nout Wardenburg

Dafne Schippers, Churandy Martina and Femke Bol are among the 24 athletes selected to represent the Netherlands at the World Athletics Relays Silesia 21 on 1-2 May.

Dutch team selected for Silesia

The Polish Athletic Association (PZLA) has announced a team of 44 athletes to compete on home soil at the&nbsp;World Athletics Relays Silesia 21&nbsp;on 1-2 May.
The host nation will have teams in every event at the&nbsp;Silesian Stadium in Chorzow,&nbsp;including the 4x100m, 4x200m, 4x400m,&nbsp;2x2x400m and shuttle hurdles relay.
The squad includes&nbsp;Jakub Krzewina, who anchored Poland's 4x400m team to a world indoor record when winning gold at the 2018 World Athletics Indoor Championships in Birmingham.
Patryk Dobek, who claimed 800m gold at the&nbsp;European Athletics Indoor Championships in Torun last month, has been selected for the 4x400m and 2x2x400m, with European 800m silver medallist&nbsp;Joanna Jozwik joining him in the 2x2x400m squad.
Ewa Swoboda, who won the 2019 European indoor 60m title, has been named for the 4x100m and 4x200m.
Malgorzata Holub-Kowalik and Patrycja Wyciszkiewicz-Zawadzka formed part of Poland's winning women's 4x400m team at the last edition of the World Athletics Relays in&nbsp;Yokohama in 2019 and will also return to action in&nbsp;Silesia.
<h3>Polish team for Silesia</h3>
WOMEN 4x100m:&nbsp;Klaudia Adamek, Paulina Guzowska, Jagoda Mierzynska, Marika Popowicz-Drapala, Pia Skrzyszowska, Katarzyna Sokolska, Magdalena Stefanowicz, Ewa Swoboda 4x200m:&nbsp;Klaudia Adamek, Kamila Ciba, Marelna Gola, Paulina Guzowska, Marika Popowicz-Drapala, Pia Skrzyszowska, Ewa Swoboda 4x400m:&nbsp;Iga Baumgart-Witan, Aleksandra Gaworska, Malgorzata Holub-Kowalik, Natalia Kaczmarek, Kornelia Lesiewicz, Joanna Linkiewicz, Natalia Widawska, Patrycja Wyciszkiewicz-Zawadzka
MEN 4x100m:&nbsp;Adrian Brzezinski, Dominik Kopec, Karol Kwiatkowski, Rafal Pająk, Mateusz Siuda, Przemyslaw Slowikowski, Lukasz Zok 4x200m:&nbsp;Adrian Brzezinski, Damian Czykier,&nbsp;Dominik Kopec, Karol Kwiatkowski, Rafal Pająk, Mateusz Siuda, Przemyslaw Slowikowski, Lukasz Zok 4x400m:&nbsp;Patryk Dobek, Kajetan Duszynski, Dariusz Kowaluk, Lukasz Krawczuk,&nbsp;Jakub Krzewina, Mateusz Rzezniczak, Daniel Soltysiak, Wiktor Suwara, Karol Zalewski&nbsp; 
MIXED 4x400m:&nbsp;Kinga Gacka, Natalia Kaczmarek,&nbsp;Dariusz Kowaluk, Lukasz Krawczuk, Jakub Krzewina,&nbsp;Karolina Lozowska, Natalia Widawska,&nbsp;Karol Zalewski&nbsp; 2x2x400m:&nbsp;Patryk Dobek, Patryk Grzegorzewicz,&nbsp;Karolina Lozowska, Joanna Jozwik Shuttle hurdles relay:&nbsp;Damian Czykier, Zuzanna Hulisz, Monika Kiepura, Krzysztof Kiljan, Artur Noga, Klaudia Wojtunik

The Polish Athletic Association (PZLA) has announced a team of 44 athletes to compete on home soil at the World Athletics Relays Silesia 21 on 1-2 May.

Host Poland names 44-strong team for World Athletics Relays

There may not be World Championships places at stake in the 4x200m, but many of the world&rsquo;s leading sprinters have opted to contest the rarely-run event at the IAAF World Relays Yokohama 2019 as part of their early season preparations.
<h3> Men&rsquo;s 4x200m</h3>
Although the USA has dominated every edition of the World Relays to date, the men&rsquo;s 4x200m is one discipline they have not yet won.
Jamaica won in 2014 with a world record of 1:18.63 and then retained their title one year later with the USA being disqualified on both occasions. Canada, meanwhile, won in 2017 with USA finishing runners-up.
Canada hasn&rsquo;t put forward a men&rsquo;s 4x200m team this year; instead, the four men that carried them to victory in 2017 will contest the 4x100m in Yokohama.
This year USA has fielded a team with two sub-20-second performers in the form of Isiah Young and Remontay McClain. 400m specialist Vernon Norwood, a world 4x400m champion indoors and outdoors in 2016 and 2015 respectively, steps down in distance. 
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Vernon Norwood in the 4x400m at the IAAF World Championships Beijing 2015</div>
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Jamaica&rsquo;s squad boasts the likes of 2015 world 4x100m champion Rasheed Dwyer, 2013 world 4x100m champion Oshane Bailey, 2016 world U20 200m bronze medallist Nigel Ellis, and sub-20-second man Julian Forte.
Keen to impress the home supporters, Japan has put together a strong line-up for the 4x200m, including Olympic 4x100m silver medallists Aska Cambridge and Shota Iizuka and world 4x100m bronze medallist Kenji Fujimitsu.
South Africa&rsquo;s team is also strong. African 100m champion Akani Simbine will team up with 2015 world 200m bronze medallist Anaso Jobodwana, 20.01 performer Luxolo Adams and rising talent Sinesipho Dambile.
Paulo Andre de Oliveira has impressed in a handful of early-season races in California and leads a strong Brazilian 4x200m team in Yokohama, while Olympic 200m bronze medallist Christophe Lemaitre headlines the French team.
<h3> Women&rsquo;s 4x200m</h3>
Given the strength of their team, Jamaica clearly has every intention of holding on to their 4x200m crown.
Three of the women that contributed to their 2017 victory &ndash; Shericka Jackson, Shashalee Forbes and Elaine Thompson &ndash; will be joined by two-time Olympic 100m champion Shelly-Ann Fraser-Pryce and 2013 world 400m bronze medallist Stephenie Ann McPherson.
The championship record of 1:29.04 they set two years ago could come under threat. The long-standing world record of 1:27.46, set in 2000, may be a bit of a stretch, but there will likely be numerous revisions to the world all-time list in Yokohama. 
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Jamaica's victorious 4x200m squad at the IAAF/BTC World Relays Bahamas 2017</div>
&nbsp;
After winning in 2014, USA failed to finish in 2015 and was a well-beaten third in 2017. With the likes of 2018 NCAA indoor champion Gabrielle Thomas, 22.02 performer Kyra Jefferson and 2017 NCAA 100m champion Mikiah Brisco in their line-up, they are perhaps the only team that can match Jamaica in terms of pure speed. It&rsquo;s just a question of which team has the better baton passing.
Nigeria&rsquo;s team doesn&rsquo;t look quite as strong as the quartet that won the 4x200m in 2015, but 400m specialist Patience George and sprint hurdler Tobi Amusan will be valuable assets.
China, France, Germany and even Ecuador could all be in contention for a top-three finish, while the support will be strong for the Japanese team.
Jon Mulkeen for the IAAF

There may not be World Championships places at stake in the 4x200m, but many of the world’s leading sprinters have opted to contest the rarely-run event at the IAAF World Relays Yokohama 2019 as part of their early season preparations.

Preview: men's and women's 4x200m relay – IAAF World Relays Yokohama 2019

In the second part of our 2017 year-end review series, statisticians A Lennart Julin and Mirko Jalava look back on the best relay performances of the year.
<h3>Men&rsquo;s 4x100m</h3>
For the past two Olympic cycles, this event has belonged to the Usain Bolt-powered Jamaican team which finished first on all occasions in three Olympics and four World Championships with the margin to second place averaging an astounding 0.71.
But nothing in sport is forever and the World Championships final illustrated that graphically on the anchor leg when Bolt&rsquo;s hamstring cramped and sent him crashing to the ground when trying to make up a three-metre deficit.
The shock of seeing this fall of an icon in his last ever race made most onlookers miss what happened at the front, which was unfortunate because, in spite of Jamaica&rsquo;s absence, the stride-for-stride duel down the homestretch between the hosts and the USA produced performances for the history books.
With 37.47, winners Great Britain and Northern Ireland became the No.3 nation of all time and the 37.52 for silver medallists USA was the fastest ever non-winning time.
&nbsp;
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Usain Bolt in the 4x100m at the IAAF World Championships London 2017</div>
&nbsp;
With Jamaica out and Canada missing their ace Andre De Grasse, the bronze went to Japan, half a second behind the top two but also a couple of metres ahead of everybody else. What is quite remarkable about the Japanese team is that it did not include two of their three individual semi-finalists.
At the IAAF World Relays two years ago, the USA had won in a blazing North American record of 37.38 and they retained that title this year, despite running a second slower. Their 38.43 was sufficient for a win, due to a large extent to botched exchanges by the other main contenders Jamaica, Canada and Great Britain.
<h3>Men&rsquo;s 4x400m</h3>
This event has been almost monopolised by the US all through the history of the World Championships finishing first in all finals but 1983 and 1991. Checking the sum of the team members&rsquo; season&rsquo;s bests made another US win look imminent: USA averaged 44.26 vs 44.99 for Botswana and 45.23 for Trinidad and Tobago.
This outlook was strengthened after the heats where the USA was fastest, despite resting their top two, while assumed main opponents Jamaica &ndash; who had finished second to the USA at the World Relays in April &ndash; and Botswana were eliminated. Jamaica, who missed out by just 0.10, in hindsight perhaps may have regretted resting their two individual finalists. 
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Lalonde Gordon anchors Trinidad and Tobago to 4x400m gold at the IAAF World Championships London 2017</div>
&nbsp;
That relays are something much more intricate than the arithmetic sum of the team members was once more proven in the World Championships final. The USA followed their traditional strategy of going for a clear lead on the first leg but this time they were unable to keep that advantage. However, with 43.70-runner Fred Kerley getting the baton first in the final exchange, another gold medal seemed all but guaranteed.
But Kerley was tired from competing continuously since January while Trinidad and Tobago&rsquo;s Lalonde Gordon was full of energy and inspiration. He shadowed Kerley all the way and with just some 25 metres to go, he managed &ndash; in a move reminiscent of Kriss Akabusi&rsquo;s in Tokyo in 1991 &ndash; to edge slightly ahead, claiming an upset win.
Great Britain was the only other team to dip under 3:00, although Belgium (with three Borlees in the team) and Spain came close.
<h3>Other relay events</h3>
With the World Relays returning to the calendar after a break in the Olympic year, there was global action also in the 4x200m and the 4x800m. In Nassau both those events quickly became tight head-to-head battles between two teams.
In the 4x200m it was Canada vs the USA. As the two teams were quite evenly matched in pure sprinting capacity, the decisive factor probably was that three quarters of the Canadian team had been part of a DNF in the 4x100m the previous day and thus had extra hunger for success.
Of course, having Olympic medallist Andre De Grasse in the team &ndash; and avoiding significant problems in all three exchanges &ndash; also helped to get the win in 1:19.42 with a margin of almost half a second to the US team. 
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Andre de Grasse of Canada in the 4x200m final in Nassau</div>
&nbsp;
In the 4x800m, Kenya and the USA left the other teams behind after just one lap of the first leg. At the first changeover, they had already put almost a second of daylight between themselves and the third team. On the second leg, Kipyegon Bett, with his 1:46.73, gave the Kenyan team a clear lead at halfway.
But Casimir Loxsom, through a 52.00 first lap on the third leg, put the USA back in contact and from then on the two teams kept together. Olympic bronze medallist Clayton Murphy &ndash; confident in his finishing sprint &ndash; just bided his time until some 50 metres remained before changing gears and overtaking Olympic fifth-place finisher Ferguson Rotich to claim the title for the USA.
<h3>Women&rsquo;s 4x100m</h3>
It&rsquo;s all even at the top of the women&rsquo;s 4x100m.
Before the IAAF World Championships London 2017, United States and Jamaica were tied with three wins each from the previous six major championships. The season started at the IAAF World Relays with a strong US team not finishing their race and Jamaica in second place in an umimpressive 42.95.
Germany, with 42.84, was fastest in Nassau. While this was not a huge surprise &ndash; as Germany has had several good performances and fast times outside major championships &ndash; their latest medal in this event is still the bronze from 2009.
In London it was hosts Great Britain who posed the biggest challenge to the United States. The USA were fastest in the heats, clocking a 41.84 world lead, but Great Britain was just 0.09 behind in a 41.93 season&rsquo;s best. In the final, United States was only 0.02 seconds faster, but still a clear winner in a world-leading 41.82 with Great Britain in silver medal position, clocking 42.12. Jamaica was a close third in 42.19 with Germany finishing in 42.36 for fourth place.
&nbsp;
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Tori Bowie anchors the USA to 4x100m victory at the IAAF World Championships London 2017</div>
&nbsp;
The USA&rsquo;s clocking of 41.82 is the slowest winning time at a major championships since 2009, when Jamaica won in 42.06 at the IAAF World Championships in Berlin.
Switzerland clocked a 42.50 national record in the heats and finished in fifth place in the final in just fractionally slower 42.51. China was disqualified in the heats in London, but Su Minxiang team won the National Games in September in 42.59, the fastest Chinese time since 1997.
<h3>Women&rsquo;s 4x400m</h3>
The USA has won 10 of the past 12 major titles on offer in this event, indoors and outdoors, since the 2008 Olympics. And looking at the individual runners&rsquo; results, there was only one favourite for the women&rsquo;s 4x400m crown in 2017.
United States started well with a clear win and an early 3:24.36 world lead at the IAAF World Relays in Nassau in April. At the IAAF World Championships in London, USA came up with a strong heat, easily the fastest of all teams in a world-leading 3:21.66.
Defending champions Jamaica was the second fastest in the heats with 3:23.64, but their final ended after second-leg runner Anneisha McLaughlin-Whilby suffered an injury within the first 100 metres of her lap.
The USA dominated the final; anchor-leg runner Phyllis Francis, the individual world 400m champion, didn&rsquo;t even have to look behind her as she crossed the line in 3:19.02, the fastest time in the world since the 2012 London Olympics and 0.04 faster than their winning time at the Rio 2016 Olympic Games.
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Phyllis Francis anchors USA to gold in the 4x400m at the IAAF World Championships London 2017</div>
&nbsp;
Finishing in second place, Great Britain grabbed only their second silver medal in the history of this event at the World Championships; their first one came in 2013. Poland was a close third in 3:25.41 and the bronze medal was country&rsquo;s first medal in this event outdoors.
<h3>Other relay events</h3>
Jamaica was fastest in the 4x200m at the IAAF World Relays, setting a national record of 1:29.04 to take the victory. Germany was second in 1:30.68 and United States third, clocking 1:30.87.
The multinational Tumbleweed Track Club, anchored by Dafne Schippers, set a world lead of 1:28.77 at the Florida Relays in Gainesville in April, with the University of Washington just 0.01 seconds behind.
In Nassau United States was the 4x800m winner in 8:16.36, a world lead for the team anchored by Charlene Lipsey. Belarus was second in 8:20.07 and Australia third in 8:21.08.
Mirko Jalava (women&rsquo;s events) and A Lennart Julin (men&rsquo;s events) for the IAAF

In the second part of our 2017 year-end review series, statisticians A Lennart Julin and Mirko Jalava look back on the best relay performances of the year.

2017 end-of-year reviews – relays

Less than 24 hours after cursing their luck &ndash; and indeed their mistakes &ndash; in the 4x100m final, Canada found redemption in Nassau on Sunday night (23), defeating sprint superpowers USA and Jamaica to claim the 4x200m title in superlative fashion.
From the outset, they made their intentions known at the front of the race, with Gavin Smellie &ndash; who had a controversial false start rescinded in the heats earlier in the night &ndash; handing over to Brendon Rodney in slick fashion. After a strong leg, Rodney passed off to Andre De Grasse marginally in front of the US and Jamaica at the halfway mark.
De Grasse was impressive on the third leg, despite facing an opponent of the highest calibre. Three lanes to his right was Isiah Young, a 19.86 athlete, who the Olympic 200m silver medallist steadily reeled in down the back straight.
At the final handoff, Canada&rsquo;s was the quicker exchange, with Aaron Brown getting into full sprint a fraction of a second ahead of USA's Ameer Webb, setting the scene for a thrilling finale.
Webb, however, had two metres to find on Brown, and try as he might that was never going to be realistic, given the Canadian has clocked 20.00 for the distance.
Approaching the line, the emotions visibly erupted for Brown, and with the ghosts of Saturday night&rsquo;s dropped baton firmly behind them, he raised his arms into an X-celebration as he brought his nation home to victory in 1:19.42.
"It did not go well yesterday but I'm glad we were able to break the curse, get the monkey off our backs and show the world what we are able to do in the relays."
De Grasse, meanwhile, paid tribute to his teammates. "It was a great run by all of us," he said. "We just wanted to keep the stick today, but we told each other to trust each other and be patient. If we could do that, we could come away with the gold today."
The US took second in 1:19.88, with Jamaica third in 1:21.09.
"Of course, we always come into the race shooting for the gold, but it was the first time in the last three years that we got the stick around," said Isiah Young. "That's already good, and we also came away with a silver medal."
Cathal Dennehy for the IAAF

Less than 24 hours after cursing their luck – and indeed their mistakes – in the 4x100m final, Canada found redemption in Nassau on Sunday night (23), defeating sprint superpowers USA and Jamaica to claim the 4x200m title in superlative fashion.

Men's 4x200m final – IAAF/BTC World Relays Bahamas 2017

Canada exorcised the demons of Saturday night&rsquo;s dropped baton with a commanding performance in the heats of the men&rsquo;s 4x200m on Sunday evening (23), but it wasn&rsquo;t without controversy.
After an apparent false start, lead runner Gavin Smellie was issued a red card ahead of the first heat, but the Canadian argued his case with officials over the ensuing minutes, the end result seeing his baton handed back to him and the red card withdrawn.
&ldquo;There was maybe a little twitch, but I didn&rsquo;t move,&rdquo; said Smellie afterwards. &ldquo;I was asking the officials to watch the video to see there was no false start. I&rsquo;m happy we got back in.&rdquo;
After a clean start second time around, Smellie ran a strong opening leg, handing over to Brendon Rodney who powered through the second leg to put his team in front at halfway.
Andre De Grasse was next up for the Canadians, and the Olympic 200m silver medallist extended their lead over Jamaica, giving Aaron Brown an eight-metre advantage ahead of the final leg.
With Jamaica&rsquo;s Warren Weir in hot pursuit, Brown had to run a strong opening half of his leg, but approaching the finish he had enough in command to ease off the throttle and coast across the line, bringing his team to victory in 1:21.11.
Jamaica took second in 1:22.01, with Trinidad and Tobago third in 1:22.79, a national record. Kenya finished a creditable fourth, their time of 1:23.04 enough to see them through to the final.
With the gauntlet laid down, the second heat saw a response in kind from Canada's neighbours and rivals, the United States. They were led off by Noah Lyles, who blazed through his opening leg and handed off with precision to Jarrion Lawson. He consolidated their advantage on the second leg before a cautious, but safe, exchange with Isiah Young.
There was a brief moment of anxiety for the USA at the final exchange, as Young ran up on anchor athlete Ameer Webb, but Webb adjusted his stride accordingly approaching the end of the zone and escaped with baton in hand. He cruised down the home straight to bring his team home in 1:21.47.
Behind them, Shavez Hart of The Bahamas powered through to take second in 1:23.71, with China a close third in 1:24.01. A national record of 1:24.33 from Antigua &amp; Barbuda saw them take fourth and advance to the final as a non-automatic qualifier.&nbsp;
Cathal Dennehy for the IAAF

Canada exorcised the demons of Saturday night’s dropped baton with a commanding performance in the heats of the men’s 4x200m on Sunday evening (23), but it wasn’t without controversy.

Men's 4x200m heats – IAAF/BTC World Relays Bahamas 2017

An IAAF/BTC World Relays record in the women's 4x200m and yet another dramatic finish in the men's 4x100m were among the key highlights on the first day of the IAAF/BTC World Relays Bahamas 2017,&nbsp;with plenty more drama on tap when competition resumes this evening.
Jura Levy, Olympic 400m bronze medallist Shericka Jackson, Sashalee Forbes and double Olympic champion Elaine Thompson dominated gun-to-tape en route to their 1:29.04 performance to knock 0.41 from the competition record set by the USA two years ago.
This time around and well after Thompson crossed the line fist raised to the sky, the USA squad could do no better than third, after Gina Lukenkemper out-dueled Shalonda Solomon down the homestretch to give Germany surprise silver. [<a href="https://www.iaaf.org/competitions/iaaf-world-relays/iaafbtc-world-relays-bahamas-2017-5978/news/report/women/4x200-metres-relay/final">report</a> | <a href="https://www.iaaf.org/competitions/iaaf-world-relays/iaafbtc-world-relays-bahamas-2017-5978/results/women/4x200-metres-relay/final/result#resultheader">results</a>]
The USA, out to defend their back-to-back Golden Baton honours, fared better in the men's 4x100m and women's 4x800m, collecting convincing victories to retain those respective titles and carry an 11-point lead into day two.
In the evening-capping men's 4x100m, showdowns between the USA, Jamaica and Canada never quite materialised: Canada missed their exchange between runners two and three while Jamaica suffered a similar fate and couldn't even manage to advance from the opening round heat. The last remaining challenge to the USA, an in-form British squad, also fell by the wayside when they botched the final exchange. That left Justin Gatlin alone at the front en route to their 38.43 win. Barbados was a distance second in 39.18 with China third.&nbsp;[<a href="https://www.iaaf.org/competitions/iaaf-world-relays/iaafbtc-world-relays-bahamas-2017-5978/news/report/men/4x100-metres-relay/final">report</a> | <a href="https://www.iaaf.org/competitions/iaaf-world-relays/iaafbtc-world-relays-bahamas-2017-5978/results/men/4x100-metres-relay/final/result#resultheader">results</a>]
The evening's first final was deja vu all over again at Thomas A Robinson Stadium, with the USA winning their third straight title in the women's 4x800m. Chanelle Price, Chrishuna Williams, Laura Roesler and Charlene Lipsey won by nearly four seconds over Belarus in 8:16.36 with Australia taking third.&nbsp;[<a href="https://www.iaaf.org/competitions/iaaf-world-relays/iaafbtc-world-relays-bahamas-2017-5978/news/report/women/4x800-metres-relay/final">report</a> | <a href="https://www.iaaf.org/competitions/iaaf-world-relays/iaafbtc-world-relays-bahamas-2017-5978/results/women/4x800-metres-relay/final/result#resultheader">results</a>]
<h3>Day 2 expected highlights&nbsp;</h3>
Competition kicks off at 19:35 local time (GMT+4) with the heats of the men's 4x200m before the inaugural mixed 4x400m brings down the curtain at 22:30.
In the latter, the focus will fall firmly on the hosts, with Bahamian golden girl Shaunae Miller-Uibo, the Olympic 400m champion, and Steven Gardiner, the current world leader in the event, expected to compete.
Although neither team advanced to Sunday's final, both ran impressively in Saturday's 4x400m heats, with Miller-Uibo's 50.20 split the fastest of the round.
The men's 4x400m is shaping into a showdown between the USA, Trinidad &amp; Tobago and Jamaica. Botswana looked strong as well in the heats, propelled by Karabo Sibanda whose 44.82 was the fastest split of the opening round.
It'll likely be a similar scenario on the women's side with the focus on USA, Jamaica and an inspired Polish team.
The men's 4x800m, meanwhile, will present Kenya's best chance to bounce back from a sub-par opening day, entering the race as podium favourites alongside defending champions USA and Poland. Alongside them, the Athlete Refugee Team will be making their eagerly awaited IAAF World Athletics Series debut.
Action also gets underway in the women's 4x100m, where yet another USA-Jamaica showdown is expected.
Bob Ramsak for the IAAF

An IAAF/BTC World Relays record in the women's 4x200m and yet another dramatic finish in the men's 4x100m were among the key highlights on the first day of the IAAF/BTC World Relays Bahamas 2017, with plenty more drama on tap when competition resumes this evening.

Looking back and moving forward: day 2 preview – IAAF/BTC World Relays Bahamas 2017

Propelled by a strong opening leg by Jura Levy, Jamaica powered to a convincing victory in the women's 4x200m, clocking a 1:29.04 competition record in the process.
The foursome &ndash; which included Olympic 400m bronze medallist Shericka Jackson, Sashalee Forbes and anchored by double Olympic champion Elaine Thompson&nbsp;&ndash; made up for another quartet's botched exchange two years ago by putting on the finest exchange-and-carry display of the first night's competition, extending their lead with each leg.&nbsp;
By the time Thompson got the baton, she was handed a full second lead, one she extended to more than a second-and-a-half before crossing the line.&nbsp;
"We came out and passed the baton around good," said Thompson, whose homestretch display was reminiscent of her triumphant half lap run in Rio. "There was no pressure, we came on the track and do what we do. We made sure we secured a spot in the finals earlier tonight and just came and do what we do."
While their exchanges were clean, the USA squad, the co-favourites coming in, was never quite in the hunt, struggling to eat up the gap that Levy and Jackson built. The German quartet, perhaps inspired by their opening round run where they finished just 0.10 behind the US team, improved on that considerably, taking the runner-up spot due largely to Gina Luckenkemper's strong anchor leg. They clocked 1:30.68 to finish one podium step higher than in 2015.
The USA were third a few strides back in 1:30.87. Further back, Trinidad and Tobago were fourth in 1:32.68 with Nigeria, the 2015 winners, fifth this time in 1:33.08.
Bob Ramsak for the IAAF

Propelled by a strong opening leg by Jura Levy, Jamaica powered to a convincing victory in the women's 4x200m, clocking a 1:29.04 World Relays record in the process.

Women's 4x200m final – IAAF/BTC World Relays Bahamas 2017

Strong runs by US and Jamaican quartets in the women's 4x200m kicked off the third edition of the IAAF World Relays, setting up yet another showdown between the two sprint powerhouses in this evening's final.
In the first heat, Dezerea Bryant and Tiffany Townsend combined to give the US a small but visible lead over France after the opening 400 metres, one padded by Felicia Brown with a solid leg three.
The surprise of the race &ndash; and the opening round&nbsp;&ndash; came in the form of Lisa Mayer who lifted an inspired German team with her anchor dash. Instead of watching US anchor Phyllis Francis pull away, the 20-year-old German caught and eventually passed the Olympic 4x400m champion. After a stride-for-stride battle over much of the homestretch, Francis eventually pulled away to edge her German rival by just .10 in 1:31.06.
Further back, Michelle-Lee Ahye closed well for Trinidad and Tobago, overtaking French anchor Estelle Perrossier off the final bend to finish third in 1:32.62, a national record.
Even with a sluggish first exchange between Jamaica&rsquo;s double Olympic champion Elaine Thompson &ndash; who received the round's most vociferous welcome from the Thomas A Robinson Stadium crowd&nbsp;&ndash; and Olympic 400m bronze medallist Shericka Jackson, the Jamaican quartet were never seriously threatened en route to their 1:31.29 victory in the second heat.
Defending champions Nigeria finished a distant second in 1:33.78 with China a few strides further back in third, crossing the line in 1:33.99 to break the Asian record. The British Virgin Islands were fourth in 1:34.92, a national record run that propelled them to the final as well.
With just nine teams competing, the Kenyan quartet was the only squad eliminated. Nonetheless, their 1:40.65 effort was also a national record.
Bob Ramsak for the IAAF

Strong runs by US and Jamaican quartets in the women's 4x200m kicked off the third edition of the IAAFWorld Relays, setting up yet another showdown between the two sprint powerhouses in this evening's final.