Analyzing Nationals to Pac Pacs Improvement

by Barry Revzin 47

August 17th, 2018 National, News

How well did the US team perform at Pan Pacs? There was a lot of concern and speculation over the effects of the long trip to Japan without sufficient time to acclimate to the time change as well as the short gap between Nationals and Pan Pacs. To that end, I thought it would be interesting to look at performance differences from Nationals to Pan Pacs. Pan Pacs is the major international meet of this calendar year, so the goal is surely for the US team to perform at its best there. Did they improve on their times from Irvine in Tokyo? There are certainly many confounding factors, and we have no way of knowing who was rested and to what extent at each meet (although obviously no one is ever rested). To simplify even further, I went ahead and just took the fastest time everyone recorded at each meet rather than just worrying about Prelims vs Finals. This isn’t entirely unreasonable, as for the US, the “B” Final at Pan Pacs is pretty significant too – and even Prelims for some events had the same kind of pressure attached to it!

Just looking at this one pair of meets gives us one data point, which wouldn’t say much of anything, so I also took as comparison the six previous years’ pairs: Nationals vs PanPacs in 2010 and 2014, Olympic Trials vs the Olympics in 2012 and 2016, and Nationals vs Worlds in 2013 and 2017 (the other two Worlds had their teams decided the previous year, so would not make for a meaningful comparison). Sometimes, an image can convey the message quickest. Here is a boxplot looking at the improvement in times from the national meet to the international meet, by year:

A negative number on the y-axis indicates that a swimmer in an event improved from Nationals/Trials to the appropriate International meet (whether the Olympics, Worlds, or Pan Pacs). For five of these seven years, the meat of the distribution is the same: half of the data ranges from -0.87% to +0.35% (that is, a 0.8% improvement to a 0.3% regression), and the median is negative in each year(from a 0.54% median improvement in 2013 to a 0.10% median improvement in 2017). You can see the thinly dotted lines marking out the common area. You might say the dotted area is a good guess for what the distribution should be.

But in 2014 and 2018, this box shifts up by nearly a half percent. These are the only two years with positive median, +0.30 and +0.20% respectively. The interquartile range is -0.39% to +0.90% for 2014 and -0.26% to +0.69% this year. In the other years, the worst 25th percentile was -0.71% and the worst 75th percentile was +0.35%. All sizeable, and visibly noticeable, differences.

Why might this be?

One popular fan theory, expressed on the comments under this article and in others, is that we simply do not care about Pan Pacs as much as we care about Worlds or the Olympics. But in the above chart, while 2014 and 2018 are quite different from the two Worlds and two Olympics years shown, 2010 is right in line with them. What was different about 2010? In all three years, Pan Pacs started 11 days after Nationals ended. It’s not that athletes simply had more rest in that one year. But while this year they had to travel to Tokyo (an 8 hour time change), and in 2014 they had to travel to the Gold Coast (a 7 hour time change), in 2010 Pan Pacs were held in Irvine. The very same place as Nationals. No travel, no time acclimation necessary. Perhaps it is the short turnaround with the long time change that is the cause of this nearly-half-percent regression, and not the fact that those athletes representing Team USA just don’t care as much.

Here’s a different way of looking at the same chart above. It’s all the same data, but I merged the 4 World and Olympic years together in the same distribution, as well as Pan Pacs in 2014 and 2018 (but kept the 2010 Pan Pacs separate) for clarity:

Improvement into the four “major” international meets and improvement into Pan Pacs in 2010 is quite similar – 2010 was about a little bit worse, but only by a tenth of a percent. But 2014 and 2018 were dramatically worse:

25% 50% 75%
worlds + olympics -0.81% -0.35% +0.24%
pan pacs 2010 -0.73% -0.18% +0.35%
pan pacs 2014, 2018 -0.33% +0.24% +0.77%

While the headline story of Pan Pacs going away will probably be our performance in the relays, and the commentator’s performance in announcing them, I can’t help but wonder how this meet would’ve played out if we gave ourselves more time in between Nationals and Pan Pacs, or more time to adjust to the time difference. The athletes themselves aren’t making excuses for their personal performances, but maybe we should?

EDIT: The original version of this article only focused on the years 2016-2018. The new version adds 4 more meets (2010,2012,2013,2014), which notably include two more Pan Pacs years, allowing for a more meaningful comparison.

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Jim C

Instead of just comparing this year to the past 2 years, I would like to see a comparison to the past 4 years. I would particularly like to see an apples to apples comparison with the last Pan Pacs. The swimmers might not be making public excuses, but I am sure the swimmers do not view Pan Pac performance like world or Olympic performance. I doubt that finishing 3rd in the 200 bothers Ledecky as much as tying for 2nd last year.


This is a good point. Pan Pacs in 2014 was also a very short turn around (last day of Nationals in Irvine was August 10th, and then 1st day of Pan Pacs in Gold Coast, Australia was August 21st).

I updated the chart to include 2014 as well as 2013. Note the similarity between 2014 and 2018, and 2013 to 2016 and 2017. The meet in 2013 was even better, ranging from -0.92% to +0.29%, but otherwise in line with 2016 and 2017. In 2014, the box goes from -0.38% to +0.84%, again very much in line with 2018’s -0.28% to +0.68%.


… and updated again to go back to 2010, which ended up being a very valuable exercise.

Stuart C

Last swim date of 2016 Olympic Trials to First date of 2016 Olympics – 33 DAYS Last swim date of 2017 Nationals to First date of 2017 Worlds – 22 DAYS Last swim date of 2017 Nationals to First date of Pan Pacs – 11 DAYS Biggest time drops by .5% mentioned above are: (2016) 44%, (2017) 33%, (2018) 17%. Conclusion! USA Swimming did not give athletes the best chance to perform. If you look at time between college conference championships and NCAA Champs, it approximates 30 days! You can ramp up yardage and intensity, and drop down again and do a 2nd taper in 30 days. You cannot do that in 11 days. The whole idea of maintenance from… Read more »


I would rather USA Swimming spend their money in 2020 than in 2018.

Jim C

It is not just money, A double taper this year would be a bad thing for athletes as far as their performance in the next two years. If we give weight 100 to the Olympics, 10 to the World Championships, and 1 to Pan Pacs you should see that it makes sense to wait until after the Olympics before deciding whether it was a good idea to do what we did this year.


Can you elaborate on why a double taper this year would be bad for the next two years?

This is the $64,000 question. Or why a double taper in 2019 is bad for 2020.

Jim C

Do swimmers do a double taper just as part of their practice? Look at the way Cate Campbell benefitted from a year off from competition. Instead of wanting a double taper in Pan Pac years, why not eliminate the break between Nationals and Pan Pacs and treat it as one 8 day meet, which seems like the standard length of a big international meet?


I don’t see how trying to swim fast and tapering this year is detrimental to swimming fast in two years.

Stuart C

So what you are saying is that we should only focus on Olympics and a 4-year cycle. How boring! We have the talent and the resources (money) to swim fast in Worlds, Pan Pacs AND Olympics! All it requires is better planning and learning from past international events. In addition, athletes can get “used” to a common plan for international travel and learn from the timeline (if it is consistent). If the timeline is always different, you are always adjusting instead of learning and you cannot build a physiological adaptation timeline for your body.

Old Rocket Swimmer

I agree the above data. Another way to double check the data is to evaluate if the US swimmers performed better at the end of the Pan Pacific meet vs the beginning. of the meet Thus they become more acclimated to the time difference and travel. On the surface it seems to be. More time would have helped our team.

SuperSwimmer 2000

You’re not taking into account the importance of the meet. Part of the reason they swim faster for the Olympics is because IT’S THE FREAKIN’ OLYMPICS. Yeah, the time between meets is a factor, but it’s not the only factor to consider.


See the updated article. I don’t see a difference between the Olympics and “just” Worlds really. And more than that, I don’t even see a big difference between Olympics/Worlds and Pan Pacs in 2010.

It’s really just 2014/2018 that stand out.

SuperSwimmer 2000

Also a factor to consider is that Pan Pacs were four days, Olympics and Worlds were eight. When it’s twice and many days long, there’s much more room to space out events, even with semifinals. You had a lot of swimmers at Pan Pacs doubling up and swimming every morning, when they wouldn’t necessarily do that at Worlds or the Olympics.

Add the fact that they were allowed to swim prelim in events in which they did not qualify, and that affects performances.

Jim C

If 2012 had been a Pan Pacs year does anyone think Ledecky would have swum only the 800 and no other race?

How much does CD bench

On a side note… now that we are getting close to 10 years post super suit era… it would be great to see an analysis article. Look at how long it took the various records to be broken, see if that’s consistent with the rate that the WRs were progressing before the suits… and look at the couple records that still stand too. Just a thought. Great article though


If i am not wrong , i think that Lochte was one of the first to break one of the suited records in 2011 ( 200 IM 1.54.00 )


At that time he was the first to break a WR since 2009


*Long course world record. Didn’t he break some short course WRs in 2010? Anyways, 2010-2011 Lochte was legendary. His performance at 2011 Worlds was a thing of beauty. 1:44.44 200 free, 1:52.96 (!) 200 back, 1:54.00 (WR) 200 IM, 4:07.13 400 IM. And he won the 4×200 for the US. Will he ever see another swimmer as close to Phelps or Lochte in our lifetime that were so good among so many events?


he did as well in 2010 (200 / 400 IM Shangai ? ) – 2012 (100 IM Istanbul ? ) – i need to check those details . His 100 IM WR was beaten by a German i think not so long ago .


2010 – Dubai 200 IM WR – with Rogan next to him .


exactly , thanks