arena Swim of the Week: Shaine Casas Hits Blistering 50.56 100 Fly In Austin

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Disclaimer: Swim of the Week is not meant to be a conclusive selection of the best overall swim of the week, but rather one Featured Swim to be explored in deeper detail. The Swim of the Week is an opportunity to take a closer look at the context of one of the many fast swims this week, perhaps a swim that slipped through the cracks as others grabbed the headlines, or a race we didn’t get to examine as closely in the flood of weekly meets.

The performances delivered by Carson Foster at last week’s Austin Sectionals largely overshadowed some of the other swims we saw at the meet.

Foster dropped three massive lifetime bests in the 200 fly, 400 free and 200 back, swims that had many crowning the double IM Worlds silver medalist the best all-around swimmer in the United States since Michael Phelps.

Despite the impressiveness of Foster’s swims, none of them would’ve gotten on the podium at the 2022 World Championships, which wrapped up just a few weeks prior in Budapest. Granted, the 200 fly and 200 back were both close, but one swim from Austin that would’ve made the Worlds podium was the 100 fly done by Shaine Casas.

Casas, who has long been known primarily as a backstroker, produced a scintillating time of 50.56 in the 100 fly last weekend, crushing his previous best time (51.09) by more than half a second and becoming one of the fastest swimmers in history.

Not only would Casas have placed second to Hungary’s Kristof Milak (50.14) in the World Championship final, nearly four-tenths clear of runner-up Naoki Mizunuma (50.94), he also becomes the fourth-fastest American in history and cracks the overall top-10 all-time.

The only U.S. swimmers faster than Casas are Caeleb Dressel, Phelps and Ian Crocker, who have combined to win four Olympic gold medals and seven World Championship titles in the event.

All-Time U.S. Performers, Men’s 100 Butterfly (LCM)

  1. Caeleb Dressel (USA), 49.45 – 2021 Olympic Games
  2. Michael Phelps (USA), 49.82 – 2009 World Championships
  3. Ian Crocker (USA), 50.40 – 2005 World Championships
  4. Shaine Casas (USA), 50.56 – 2022 Austin Sectionals
  5. Maxime Rooney (USA), 50.68 – 2019 U.S. Summer Nationals

All-Time Performers, Men’s 100 Butterfly (LCM)

  1. Caeleb Dressel (USA), 49.45 – 2021 Olympic Games
  2. Kristof Milak (HUN), 49.68 – 2021 Olympic Games
  3. Michael Phelps (USA), 49.82 – 2009 World Championships
  4. Milorad Cavic (SRB), 49.95 – 2009 World Championships
  5. Joseph Schooling (SGP), 50.39 – 2016 Olympic Games
  6. Ian Crocker (USA), 50.40 – 2005 World Championships
  7. Rafael Munoz (ESP), 50.41 – 2009 World Championships
  8. Matthew Temple (AUS), 50.45 – 2021 Australian Olympic Tirlas
  9. Chad Le Clos (RSA) / Shaine Casas (USA), 50.56 – 2015 World Championships / 2022 Austin Sectionals

In June 2021, Casas swam a personal best time of 51.22 in the 100 fly just days after the conclusion of the U.S. Olympic Trials. He opted not to race that event in Omaha, and would’ve finished third in the final, just three one-hundredths shy of second, had he gone that time there.

The event then appeared to be one of his main focuses in 2022, as the 22-year-old rattled off a pair of 51-lows at the San Antonio Pro Swim in late March, bringing his PB down to 51.09 in the final.

However, he surprisingly dropped the event from his program at the U.S. International Team Trials in April, avoiding a potential scheduling conflict with the 200 back.

While he would end up going on to win bronze in the 200 back at the World Championships, one has to wonder what might’ve been had he gone for the 100 fly in Greensboro and ultimately Budapest.

Split Comparison

Casas, March 2022 Casas, July 2022
23.75 23.42
51.09 (27.34) 50.56 (27.14)

While it’s impossible to know whether or not Casas could’ve mustered a time slightly quicker in Budapest and legitimately challenged Milak for the gold medal, there’s no doubt it should be a target for the former Texas A&M Aggie moving into the next two years.

It’s also hard to gloss over the fact that Casas is now training under one of the best 100 fly coaches in recent history, Eddie Reese, who has coached the likes of Ian Crocker (former world record holder, two-time world champion), Joseph Schooling (2016 Olympic champion) and a large number of men who have had success in the event at the NCAA level.

And like Foster, Casas appears to be really coming into his own and developing a wide range of events that could potentially be on his major event schedule in the coming years. Having won bronze in the 200 back at the World Championships, Casas also hit new best times in the 100 back (52.51, would’ve been .05 shy of making the Worlds team) and 100 free (48.23, would’ve qualified for U.S. 400 free relay) in Austin.

He’s also a future challenger in the 200 IM, if he opts to go that route, having gone 1:56.70 at the San Antonio Pro Swim, a time that would’ve also been just five one-hundredths shy of making the Worlds team at U.S. Trials.

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6 months ago

“Blistering” is a bit of an overstatement when it’s over a second behind the WR in a 100m race.

Steve Nolan
6 months ago

The US top five is three insanely well decorated butterfliers up top, and two dudes that might never swim the event at an Olympics/WCs.

6 months ago


Reply to  TheMainMane
6 months ago
Knocking Down Phelps Any Way I Can
6 months ago

It’s faster than Phelps ever went in a textile suit. Just a reminder that Phelps swam a 51.21 to win gold at the 2012 Olympics, then got silver 4 years later with a 51.14. (Michael Andrew has also been faster than those times.)

Reply to  Knocking Down Phelps Any Way I Can
6 months ago

Phelps went 50.45 at the 2025 US Summer Nationals, which at the time was the second fastest time ever in a textile suit only behind Ian Crocker’s 50.40.

Last edited 6 months ago by IM FAN
Reply to  IM FAN
6 months ago

not sure this date is correct

Inside Smoke
Reply to  bob
6 months ago

It is, just give it a few years

6 months ago

He’s got some tough choices to make… a genuine medal contender in both backstrokes and 100 fly… and I would say 200 IM if he could bring himself to swim it. Anyone know if he’ll be swimming at nationals, or taking a break a la Foster?

Reply to  Caleb
6 months ago

He will be at Nationals.

6 months ago

I’m hoping Shaine’s gotten the hint and that he doesn’t scratch the 1 fly at the next trials meet.

6 months ago

keep in mind his decision was made not to swim this at worlds when Caeleb Dressel was still swimming it and his best time was a 51. For him to get a silver he would have to go this time and Caeleb Dressel not swim the even. For him to qualify for the US team he would have had to beat Mike Andrew and Caeleb Dressel which would have required a time like this at trials.

Either way this is a great swim and further demonstrating his incredible versatility.

About James Sutherland

James Sutherland

James swam five years at Laurentian University in Sudbury, Ontario, specializing in the 200 free, back and IM. He finished up his collegiate swimming career in 2018, graduating with a bachelor's degree in economics. In 2019 he completed his graduate degree in sports journalism. Prior to going to Laurentian, James swam …

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