Numbers, Numbers, Numbers: the Numbers Behind Tomoru Honda’s World Record 200 FLy

Japanese swimmer Tomoru Honda took a surprise World Record in the 200 fly (1:46.85) on Saturday, breaking the old record of 1:48.24 set by countrymate Daiya Seto.

World Records generate a ton of interest, and with that interest comes a ton of data. Below, we’ve compiled some of the most interesting ways to look at the result and what it means for swimming and Honda.

Back-Half Splitting

When Honda set his surprise World Record on Saturday in Tokyo, the primary difference-maker was his back-half splitting.

Honda’s splits:

• 24.29
• 27.10
• 27.44
• 28.02

Honda opened in 51.39 – which would have been the World Record in the 100 meter fly as recently as 1998. But that was actually slower than the old World Record pace, where Seto was 51.29 in his first 100 meters.

But he closed in 55.46, which is a second-and-a-half better than Seto was in his closing 200.

This is not dissimilar from the approach that we’ve seen from the long course World Record holder, Kristof Milak of Hungary, who has used back-half swimming to leave Michael Phelps’ World Record in the event in the dust.

What’s interesting is that this is actually against the run of play for how the most recent 200 meter male World Record holders have set their standards. Three other 200 meter World Records have been broken in the last decade:

Men’s 200 SCM Back Relative Splitting:

Men’s 200 SCM Breast Relative Splitting:

Men’s 200 LCM Breast Relative Splitting:

The older World Records, mostly from the 2009 polyurethane supersuit era, were more like the current ones – back-half swims. That is most likely an impact of those polyurethane suits, which were widely considered to provide most of their benefit at the end of a race. When Aaron Peirsol went 1:51.92 at the 2009 World Championships in the 200 LCM backstroke, for example, he was a second faster over the last 100 meters than Ryan Lochte’s 2008 World Record. Lochte never got the World Record back again, but he continued to drop his back-half results in the post-suit era.

Honda is a good closer in the 200 fly in long course as well – though next to Milak, everyone’s back-half looks slow.

The question that remains to be answered has four possibilities: have the 200 butterfliers figured something out that the 200 breaststrokers and 200 backstrokers haven’t? Is Honda reacting to Milak’s closing speed by developing his own? Is the 200 fly a different 200 meter event than the other 200 meter events?

Or is the difference more benign – just the coincidence of two swimmers with a preference for back-half racing?

Breaking World Records against World Record Holders

It takes a special kind of cold-blooded swimmer to take a World Record away from the current World Record holder while that current World Record holder is in the same race. That’s what happened on Saturday, when Honda took the record away from Daiya Seto.

Below is a list of all current World Record holders who took the record away from the former record holder in the same race. When a swimmer has broken the record multiple times in a row, we’ve gone back to the last time the swimmer broke someone else’s record.

• Men’s 50 free SCM – Caeleb Dressel def. Florent Manaudou (2019 ISL Finale, Las Vegas)
• Men’s 1500 free SCM – Florian Wellbrock def. Greg Paltrinieri (2021 SC World Championships, Dubai)
• Men’s 200 breast SCM – Kirill Prigoda def. Marco Koch (2018 World Championships, Hangzhou)
• Men’s 100 fly SCM – Caeleb Dressel def. Chad le Clos (2020 ISL Finale, Las Vegas)
• Men’s 200 fly SCM – Tomoru Honda def. Daiya Seto (2022 Japan SC Nationals, Tokyo)
• Men’s 200 free LCM – Paul Biedermann def. Michael Phelps (2009 World Championships, Rome)
• Men’s 100 back LCM – Thomas Ceccon def. Ryan Murphy (2022 World Championships, Rome)
• Men’s 200 back LCM – Aaron Peirsol def. Ryan Lochte (2009 US Nationals, Indianapolis)
• Men’s 50 breast LCM – Adam Peaty def. Cameron van der Burgh (2015 World Championships, Kazan)

Women:

• Women’s 50 free SCM – Ranomi Kromowidjojo def. Sarah Sjostrom (2017 World Cup, Berlin)
• Women’s 400 free SCM – Ariarne Titmus def. Wang Jianjiahe (2018 World SC Championships, Hangzhou)
• Women’s 100 back SCM – Minna Atherton def. Katinka Hosszu (2019 ISL regular season, Budapest)
• Women’s 50 breast SCM – Alia Atkinson def. Yulia Efimova (2016 World Cup, Tokyo)
• Women’s 100 breast SCM – Alia Atkinson def. Ruta Meilutyte (2014 World Championships, Doha)
• Women’s 50 fly SCM – Therese Alshammar def. Marieke Guehrer (2009 World Cup, Durban)
• Women’s 100 fly SCM – Kelsi Dahlia def. Sarah Sjostrom (2021 ISL Final, Eindhoven)
• Women’s 400 IM SCM – Mireia Belmonte def. Katinka Hoszu (2017 World Cup, Eindhoven)
• Women’s 100 breast LCM – Lilly King def. Ruta Meilutyte (2017 World Championships, Budapest)

A few notes of note:

• Kira Toussaint swam the 50 backstroke at the 2021 World Championships where Maggie MacNeil broke her World Record, but fell out in the semi-finals while MacNeil broke the record in finals.
• Tom Dolan swam at the 2002 US Nationals where Phelps famously first broke his 400 IM World Record in a battle with Erik Vendt, but Dolan swam the 200 back that day instead.
• Liu Zige swam at the 2014 World Championships where Mireia broke her 200 fly (SCM) record in finals, but didn’t advance out of prelims.
• Ye Shiwen swam at the 2016 Olympics where Katinka Hosszu set the 400 IM World Record, but didn’t advance out of prelims.
• Michael Phelps was on the 2009 World Championship roster when Ryan Lochte broke the World Record in the 200 IM, but Eric Shanteau was the second American entry in that event in Rome.

World Records at non-World Championship Meets

Honda continues a trend of Short Course World Records being set at meets aside from the global championship for that course. Only 11 of the individual short course meters World Records have been set at the Short Course World Championships – a meet that continues to be diminutized in the view of the swimming community at large.

In long course, 22 have been set at either the World Championships or Olympics. Remember that there are more events in short course than long course thanks to the 100 IM – 38 short course events versus only 36 in long course.

In short course, the breakdown of the types of meets that short course World Records have been set in :

• World Championships – 11
• World Cups – 11
• ISL meets – 9
• National Championships – 6
• Duel in the Pool – 1
• Sub-national meets – 1
• European Championships – 1

List includes two ties.

World Record Cities

The swim by Honda is the 57th World Record that was set in Tokyo, the third-most of any city in the world. 10 of those World Records have been in butterfly races.

This list is dominated by a few factors. One is cities that often host big meets like the Olympics or World Championships, and specifically that host those big meets in key moments. Rome, for example, broke the World Record-heavy 2009 World Championships. Los Angeles has hosted the Olympics twice. Tokyo has hosted the Olympics twice (including most recently in 2021).

While more World Records have been broken in the US than in any other country, LA is the only city in the top 9 in part because the US has split its major meets among a ton of different cities in history. That’s as compared to, say, Japan, where Tokyo has hosted almost every important meet ever held in the country.

Top World Record Cities:

• Sydney – 88
• Los Angeles – 78
• Tokyo – 57
• Rome – 52
• Melbourne – 37
• Moscow – 35
• Montreal – 32
• Barcelona – 31
• East Berlin – 28
• Chicago – 27
• Long Beach – 27
• Austin – 25
• Munich – 25
• Budapest – 22
• Los Altos – 21
• London – 20
• Beijing – 19
• Indianapolis – 19
• Santa Clara – 19
• Vienna – 19

Ages of World Record Breakers

Honda is only 20 years, 299 days old – similar youth to the long course World Record holder Kristof Milak, who was born less than two months later.

Only a handful of men have held the 200 fly World Record holder in short course, and a surprising number of them have been quite young.

Honda broke his record 1 day older than Franck Esposito of France was when he set the record for the first time. Esposito broke the record two more times in his career, including a whopping 11 years later, where he became the oldest man to set it.

Of the 17 World Record performances in the event, 10 have been done by swimmers aged 22-or-younger.